Fantastic scenery! The jokes during the tour are definitely for children, but overall had a very informative tour guide and got to see some cool stuff! Price was reasonable and they have snacks available. The chips for the nachos were stale, but when youre hungry, you plow em down anyways. Would recommend!

This cave is impressive. I never believed it could be some cave like this very close to Austin. Im so glad that I had a chance to see this place. Its a package of science and history together.Its a great adventure and a fantastic place for adults and kids.

We had an amazing experience. Very smooth touring. Beautiful cavern formations.12 yo and 8 yo loved it!1. We reached there at 9:50. If we would have reached there about 10 minutes earlier, wed have saved one hour.2. Tickets are 21.95 adults and 15.95 kids and are well worth it!3. Tours leave every 20-30 minutes.4. Our tour guide was Irene and was very funny and helpful :)5. Nice restrooms at the entrance.6. Very young kids (infants) may feel claustrophobic. We noticed that with several little ones.

We loved this Cave!!! It’s a wonder underground!!!!!weather now is so hot but underground it is nice and cool. You still have to wear your masks though which can get a little uncomfortable after walking 1 mile. Our tour guide Kristina was very good and funny!! She spotted several small bags for us to watch. There’s a souvenir store inside. We took the Adventure tour and our 7 and 5 yo handled very good. Be sure to wear your tennis shoes or hiking boots since it is wet and muddy inside, also there are steep spots inside. We enjoyed it very much!!!

We had a great tour with Brendon. This was an amazing learning experience even on a rainy day. Kids under 5 or so may have a harder time with the walk (some parts of the trail can get damp and slippery). Like the website recommends, wear walking shoes with good traction and its a fairly easy mile.

Great trip with my son. We loved learning about the fossils found in the cave and exploring the different passages. My son was shocked to learn this part of Texas used to be underwater. When they shut off the lights momentarily during the tour you literally cant see your hand in front of your face. The tour guide did a great job as well. All in all it was a very enjoyable experience.

Absolutely worth the money. Fabulous tour with knowledgeable guides. Wear comfortable shoes for the 1 mile hike under Texas. The temperature is around 72° with high humidity. Definitely fun and educationally. good for young and old. Enjoy it!! My family did.

Our tour guide was so good with the kids, they hung on her every word. She answered all there questions and really knew her stuff. The place was breath taking. I loved it. Definitely will come again. Just dont forget your hiking shoes and to stretch before.

Best time ever...... Tour guide Andy made my experience unforgettable. He was nice, funny, and most of all very knowledgable.

This cave is not at all what I was expecting considering the location. Its under I-35 close to stores and restaurants. I was expecting to enter a man made overly fake tourists luring attraction -but it was not at all that! The online pictures do not even come close to how impressive it is in person. We went to the Longhorn State Park Cavern and that was so beautiful but the one at Inner Space definitely has a shocking factor to it because of the many natural formations. There was a lot of water in the cave thanks to the rain weve had lately in Texas which made the experience even more majestic. Its definitively a must see! As for the place itself, the area outside is nicely shaded and there are bathrooms inside the ticket booth area as well as a diner with a great mammoth and a gift shop; the prices are very reasonable. We went during COVID-19 and had to wear masks inside the cave and it was fine. The temperature inside the cave did not feel cold at all, our guide said the humidity is usually high so even though its a temperature change you dont feel it much. As you go in, there is a small stop where they take your picture which you can purchase later; its optional but I would recommend doing so since its not the type of place where you want to walk around with a phone in your hand....you may miss out on some breathtaking views! If youre itching for a picture, at the end of the cave there is another stop in a beautiful area where you are encouraged to take your phone out and take as many pictures as you want. I loved this cave and we cannot wait to go back.

An amazing travel through remote past to present times of earth history.Glimpse of the remains of extinct inhabitants of where we exist today.My gratitude to the builders of I-35 roadway sitting exactly above the caverns and the courageous men who dated to lower down themselves though holes from the earth surface down into the caverns.

Beautiful and unique experience but not for people with movement disabilities or breathing issues as it gets warm and humid at a few points with masks on. Tour guide was entertaining and informative.

This state park and attraction is a great place to visit with the family. It’s truly stunning. The Adventure tour was just the right amount of time and distance. We even learned some things about caves and rock formations. The temperature is very warm dress in layers if you go during the winter. On the way back out it was a 45 degree plus uphill walk and was vigorous. The wild tour is not available at this time and the hidden passage is only available during the week days and costs extra. I recommend coming here to explore. Also, shopping at the outlet mall in Round Rock is close by.

The cave itself was very cool to see, however I couldnt hear the tour guide unless you were literally right next to her. For some reason, they had 25+ people in our tour group, which I normally wouldnt mind but you literally have to squeeze together in some spaces and I really didnt like that due to COVID concerns. We also had people in our group (and our tour guide) who continuously took off their mask. Was also very bummed to find out that this was a privately owned institute. Wished the money went to the state! Experience would have been much better if they stuck to social distancing and mask wearing rules while also allowing people to reserve tours online to make the groups small.

It was awesome! Its very exciting to be inside a cave. We seen some small bats, its a very nice place to go with your family, I really enjoyed it, and I highly recommend Inner Space Cavern. This is a place I would definitely go again.

TL:DR Inner space caverns is a great 1 hr tour of a cave that doesnt require reservation when with a group less than 20.Longer read: Inner space cavern is located right off of i-35 in georgetown. Approximately 25 minutes from the center of Austin. It is easy to get to and easy to spot from the freeway.Once there, tickets cost about 23 dollars per person. Because tours leave every 20 or so minutes, its not likely that youll be waiting long for a tour of the cave. The tour guide that we had was very informative, knowledgeable, and humorous! It made what could otherwise be an educational tour into something pretty fun!The tour itself lasts about an 1hr and is approximately 0.75 miles roundtrip. It appeared that the tour was wheelchair accessible, which is a plus.My one complaint is that it **appeared** that there were too many people on the tour. If things were not so precarious right now with COVID-19, it wouldnt be a concern of mine, but I think there should have been more restrictions as to the number of people per tour. Otherwise, it was great!

Worth the 40 minute drive from Austin. Our tour guide was Michael. He was very knowledgeable. The cavern is amazing. Must see for every student.

5 Stars!! Super cool experience & worth the money. Michelle, our tour-guide, was very nice & informative! My group of 3 explorers took the Hidden Passages tour. We went at our own pace and everyone really had a great time! Lots of really impressive formations to see & you may even see some cute little bats!

I just had a tour 2 days ago after not having been here for 10+ years, back when I was on a school field trip. My brother, cousin and I all set out with a group of 6 or so more cave dwellers. It was around 1 hour with a great tour guide that explained many formations and had many stories about how the cave was found or what a rock is called by what it looks like. There is even a part at the end when they turn all the lights off and you get a sense of how dark it really is. All in all, this is a non-expensive fun and intriguing tour that I will definitely be coming back to sooner rather than later.

This place is actually really cool! However, they didn’t enforce social distancing or masks. Over half of my group of way too many people for a cave took their masks down. Our tour guide said nothing about it. So since there were no rules, they eventually took them down. It was a bit ridiculous and I didn’t feel safe. Too bad that an awesome experience was shut down by selfish people.

My kids and I really enjoyed this unique experience. This Cavern is really something beautiful and so amazing. Highly recommend!

The wonder of caves never ceases to amaze me. This wonderful cave was discovered when a bridge for IH-35 was being built in 1963. A core sample drill broke through the roof of the cave and it was discovered when a hole big enough to fit a small worker through was lowered down the hole into the pitch dark cave. The formations are beautiful and still growing. Ive been twice and will go again when they open up the more extensive tours again.

Heres what I wish I had known before we went to this cavern. My family has been venturing out and we have found most places are operating in a safe manner with masking and social distancing requirements. Unfortunately, this is NOT one of those places. There are posters on the door that state masks are required but Id estimate about a third were wearing a mask around their chin, a third below their nose, leaving only a third wearing a mask properly. One family had on masks made of sheer netting. Our tour guide wore his mask below his nose the entire time and 75% of the people on out tour took of their masks off inside the cave. There is no attempt to limit the number of people in the building and there is no way to socially distance effectively. You are literally bumping into people and kids are running around everywhere. Its even worse in the cave where the tour groups are large and many tours are in the cave at the same time (we passed five large groups in narrow passages during our tour). A few weeks ago we drove to Longhorn Caverns and it was a huge contrast because all of the appropriate safety precautions were in place there. Masks were required and visitors instructed to wear them properly even in the cave, guides wore masks properly, tour sizes were small so it was easy to socially distance and we only passed one other tour. So if you have the time to drive a little farther, I recommend heading to Longhorn Caverns instead.

Fun activity! Great tour guides that add their own spin and interesting stories to the tour. 1.5 hour tour, not too taxing and most is on level ground.

I remembered coming here as a kid! Loved it then! Took my kids this time around and they loved it! Good little trip for the day, especially after being stuck at home for so long! The staff is so good with social distancing, also I noticed that they try to keep the tour groups as small as possible, as well as encouraging distance, which is a plus! Definitely recommend for a family outing.

If you want to do something different, this place is perfect , with family, friend or alone you’re gonna enjoy it, it is a very nice place, and it is not so little, the guide was very friendly and answered our questions. My kids loved it , dress as comfortable as you can and wear shoes that don’t slip.

I havent been here in almost 30 years. This is my second visit. There was a cable car train that took you back to the surface. Thats not there anymore, so youll be walking back up. This is a great cave. Excellent mix of formations. Guide was very knowledgeable. Im 44, and the only somewhat strenuous part was the incline out of the cave. Highly recommend this cave if youre in the area.

Took my family here. The tourist was very nice and told us a lot of information about the history of the cave. If you are looking for someting to do with your family and/or friends, I recommend taking them here. The little shop is cute also. Has some unique fun things to buy.

Our guide, Rachael, was amazing. She was very charismatic and interacted with everyone. She took her time to explain everything and she fielded questions very professionally. Rachael was very sweet to our two young boys and entertained them throughout the tour. She even wrote their names on the wall with her UV light. They/we really enjoyed the experience. Thank you!

Entertaining and amusing guide. The caverns look pretty much like I remember from my elementary school field trips 40-ish years ago so that was nice.

A must visit for anyone living in the central Texas area. Their basic tour is great for families with kids and the prices are reasonable. Highly educational. The staff is great and their variety of fudge (yes I said fudge) is found in the gift shop, but it is so delicious!

Fun place to visit. These caverns are more interesting than the ones Ive been to Hill Country. Shout-out to our tour guide Cole who did a great job explaining stuff.

This was the first cavern my boys and I went to and we really enjoyed it. We learned about caves; how they form, what structures are inside and stories of discovery. Since going here we are completing our Texas Cave Trail Passport. I highly recommend a visit. Also, Rachel is a really funny, informative and fun tour guide!

Goid place to feel the cave and some history around it

Amazing! Mary was our tour guide and made us laugh! The Adventure Tour is well worth the trip from Humble, TX! 10/10 We highly recommend you go!

Great experience, cavern-wise. However, they don’t fully enforce masks, and I encountered at least 7 people without masks or partially on in my group and another group that was passing by. Also, it’s virtually impossible to stay six feet apart on this tour. They also have groups of around 15 or so per tour; this should really be under 10 right now.So know going in, this is riskier than other things you can be doing during the pandemic but if your comfort level is ok with it, then it’s worthy of your time.

Absolutely fun and awesome way to stop the car and stretch our legs on the way back home. Great walk, fun tour guides, cooler in the caves than up top, kids loved it and masks and social distancing was well observed.My kiddos absolutely loved doing the sluice bags at the end, $4.50 with an admission ticket gives them a good handful of pretty stones to remember the experience and show their friends.

Natural Cavern was amazing. Beautiful formations. My husband and I took our two kids and they loved it. Our tour guide Megan showed her passion for geology. She was knowledgeable and funny. Highly recommend!

Inner Space Cavern is a great place for a weekend family outing. The cave is beautiful inside. Katie was a great tour guide! She was very knowledgeable and enthusiastic.

I would absolutely not recommend going here during virus times, or at least not on the weekend. We felt comfortable going based on covid rules they listed and friends comments about recent visits, but nothing was enforced. Despite signs on every door, masks were hanging from ears all through the building and it was impossible to maintain distance. During the tour I saw entire families not wearing masks as were stuck two feet apart in a confined space. I assumed we would at least be limited to exposure to our tour group, but its one way in and one way out, so we had to go up against the side and let groups pass very close by several times. They also say on the website that theres no need to book ahead unless you have a large group, yet we had to wait 40 minutes because it was so busy.

Not what I was expecting at all and definitely NOT worth $22 per person. The price is ridiculous. Its just a guided tour through a cave you cant touch. Lasted I believe about 30 mins. You walk through it as the guide tells you about it an then you walk back out. They also take your picture which should be included in the $22 but of course it isnt. Wear shoes as it is very wet an watch your step, can be slippery. Wouldnt suggest taking some one that has a hard time walking. I believe they take you 78 feet under ground and then back up. Save your money an find a cave you can actually explore on your own.

The caves were great we took the adventure tour which was about half a mile and took about 1.5 hours. The guide had some good stories and funny jokes. I would suggest you bring a flashlight and wear shoes with grip. The caves are wet and some areas are muddy and steep. As we went deeper in the caves you could feel the humidity and might feel claustrophobic or maybe just me. Although there are some lights inside bring a small flashlight to light up some dark walking areas. I don’t think I would do this again $70 for 2 adults and 1 child.

I had no idea that an in-depth Cavern system was so close to where I live!! It is not as expansive as Carlsbad Cavern or some of the other ones I have visited as a kid, but this was REALLY cool. We had a lot of fun on the tour. The staff was very nice and helpful. Great tour to take a family on.

Awesome experience! It is very informative, and you have a lot more opportunities to ask a lot of questions and inquire about the nature of the cave system when youre in a smaller group. The tour guides are pretty helpful and very knowledgeable about the area, as well as the minerals and rocks. If youre fan of geology then youll really like this area, it might not have a lot of human history of some of the other caverns in Texas, but it does have a lot of geologic significance. Overall this is a great family friendly place to go to, and something you must do at least once when youre around the area!

Absolutely enjoyed this tour even during COVID. Our tour guide was John and man was he a story teller! He definitely made this experience a great one for all. My son enjoyed and learned so much. This place is as beautiful as you see in the pictures. Would most definitely recommend! Thank you inner space caverns for your wonderful staff.

Such a great experience! This place is so amazing the scenery is out of this world, so much to see! The staff is friendly, the gift shop is packed with cold items. Definitely take your kids or go there on a date it will not disappoint.

It was amazing loves it mostly would come back to it

John was an excellent tour guide! We loved his jokes and fairy tale. We opted for the Adventure Tour. Wasnt crowded and I recommend the sluicing activity for the kids after the tour. Gift shop and small cafe inside too.

My group went on the basic, 1 hour tour. We had a lot of fun! The guide was nice, and had a lot of cool facts and stories. There were some great photo spots as well. I definitely recommend it!

I enjoyed the Adventure Tour at Inner Space Cavern - educational and a great value. Allow 1.5 hours and wear good shoes. The cavern is really impressive and we learned a lot. Recommended!

We did the Candlelight tour with Elton. He was very knowledgeable of the tour and patience with us.

This is such an awesome place. The tour was amazing. Just the right number of people and the tour guide was informative and entertaining.

If you like caves this one is pretty cool & all the people there are really nice the tour is about 45 minutes 2 an hour they even offered 2 let my dog stay with them while we were on the tour so if its 2 hot or cold in the car there you go really cool place oh and dont forget 2 tip your guide

Natural Cavern was amazing. Beautiful formations. We are party of 20 peoples. Our tour guide Alvin showed her passion for geology. He was knowledgeable and funny. Highly recommend!

One of the sites we went to see was Inner Space Cavern. We took the one hour tour which takes you all the way back into the cave. Was just long enough and got see some very interesting things. Our tour guide was IBean and was very interesting kind of guy. Gave us lots of interesting information. He made the tour even more interesting. The cave was found when they were building I35. They also have a tour where it is off the regular tour where you actually go exploring and have to crawl and climb with in the parts of the cave not on the normal tour. This place highly recommended.

We had such a great time!! This is a unique experience that all of the kids enjoyed. The prices arent too crazy considering how long the tour is and how gorgeous everything was. The tour guide was very informative and answered any questions we had. We recommend!

The caverns are a wonderful step back into time

Hadnt been here in decades. So majestic and such great history!!! Going to go back asap for the spelunking adventure. Solid stop and right off I-35S!!

Good but they selling out of tickets very fast Sunday is not as busy as every day because of church too let people know

Really cool piece of Texas for a half day trip... only Cons - Little pricey, and they dont let you take strollers. So its a little tough with small children as you have to carry them the whole tour. Otherwise, it was excellent. Nicely timed tour. Our tour guide, John, was awesome and very informative. Its also a break from the Texas heat as its basically a natural air conditioner!

My family and I visited Inner Space in Monday and we were blown away! Not only is the cave absolutely beautiful but our tour guide was absolutely amazing! Rachel was very knowledgeable, funny, and seemed very passionate when she spoke. She was able to answer every question our group had and made the tour a great experience. I really attribute how great our tour was to her!

We loved learning about the fossils found in the cave and exploring the different passages. My son was shocked to learn this part of Texas used to be underwater.

Its great to disconnect and go underground. Its interesting, amazing and its also fun for the little ones. They also offer a more challenging tour for the big ones.

Very cool cave system. Kind of expensive for a family of 4. Seriously $23 per person to walk in a cave for an hour. Neat place though.

Good family fun. Really not worth the money. The day we went their debit machine was down. We had to leave and get cash. It is humid as hell down there. Good way to waste a few hours though. The decor is exactly the same that it was when I went here as a kid in the early 90s. About $85 for a family of 4.

Visiting from Florida and returned again last week with our daughter Who’s from DFW. Her first visit and we had bragged about how wonderful it was. Unfortunately our guide allowed a dad and 3 kids not wear their masks over faces the entire tour. I brought it up to him and the family at least twice when we began the tour. The guide agreed with me but did not enforce. This family did not care and wore the masks around theirs ears and pulled to the chin at best. We were disappointed ️ and distracted the whole tour. We had to dodge them and others that did not keep a safe distance. Thought you should know about Covid.

It was such a good experience, great tour guide, answering all questions and awesome information.Thank you so much!!!!

Interesting, educational tour. Guide was knowledgeable. Clean restrooms. Nice gift shop.

Nice visit. The guide was knowledgeable. We (the family) had a great time.

Great experience, steep exit (if I can make it tho u can make it lol) little pricey for what u get but the experience is a must.

What a great experience and fun awesome cave worth visit

One of my favorite caves to tour in in Texas. Cant wait to go back for The Wild Cave Tours!!

This is a nice fun event. Trying hard to not compare this place to Carlsbad Caverns. Our tour guide was knowledgeable and entertaining. Its a very short trail - about 3/4 of a mile to the end and the tour is an out and back. Oddly enough, while the temp down in the cave is mid to upper 70s, the humidity is around 98%. It gets more uncomfortable the deeper you get.Wear shoes that you dont mind getting muddy because the trail is wet and muddy.An entrance fee of $10 would raise my rating to a 4.

It was awesome, maybe they will find a bigger one, it is Texas after all.

It was really good. We thoroughly enjoyed the tour. I went with my 11 yr old daughter and my sister.

Great Caverns! Very active today with all the rain. Great staff !! Very nice Gift shop also. Bring your family.

It was different, it was cool walking under the interstate I-35 and you could hear the trucks passing over head, not loud, but could hear them.

There are much more grand caverns out there. However, this one has its own beauty and interesting facts associated with it. The number of fossils (44 species) recovered from the cavern is very interesting. The areas where the beautiful stalactite and stalagmites were, were fabulous. Im not sure it was worth the $100 for my family of 5 though.

I want to give this place a 5 star rating, but I can’t. We drove 3 hours to see these caves. And in these uncertain times I checked their website before venturing so far. “No reservations needed” and “we never sell out” were a big draw for us.We got all the way there and they were SOLD OUT!! I was shocked and very disappointed. They got 3 stars because they did give us tickets for another day. But since they only take walk ins and no reservations how can we drive all that way again?Just be aware. They need to change their website to indicate they indeed DO SELL OUT.

This is our first time visiting Inter Space caverns outside of Austin Texas. We have gone on other cave tours in California and Indiana and this was by far the best. Caroline was a great tour guide. It’s a great family activity to do when it’s hot outside. The cave is 72° and it was 98° outside. Very interesting and fun.

We had a great time and would tell everyone about how much we enjoyed our time together underground

Looked like a Disneyland diorama in the beginning. Was worried about social distancing, so we left early. Tour guide was really nice!

Inner Space Caverns is a fascinating place to visit. Ive been on three tours over the years and they never disappoint. The tour guides know their stuff and most are pretty funny. The gift shop is well appointed and nicely kept. Highly reccomend!!!

Very informative and fun exploring the cave and seeing some of the prehistoric animal bones found there .

Extremely beautiful cave with countless natural formations. Caves are different and this one is worth seeing. Tour takes a little over an hour and wear sturdy shoes. Reasonably priced.

After years of driving by we finally went on the tour it was so much fun

Very worthwhile. Tour was educational and interesting but sometimes difficult to hear with our larger group. Would like to do the more challenging cave exploring tour next time.

Great fun. Entertaining tour! Thanks John!

The beauty of nature is always spectacular. However today Grandma Texas took a friend from out of town to the caverns now I remember maybe 10 years ago there used to be a boxcar for the miners that would assist the guests down into the cave as well as back up to the surface not this time Im telling you walking out of that cave that Steep Hill the older woman in front of me I didnt think was going to make it I really think they should put on the website that there is a lot of walking uphill as well as distance.Our tour guide Gabe was knowledgeable maybe a little too much maybe you should give him a day off so he doesnt spend so much time in those caves making up stories about kings and queens that he wants to share with us.Oh dont let me forget there is no more panning for gold yes people I said there is no more they used to have it outside after you were done with your tour you would take your kids outside and yall would pan for gold what a big disappointment.For me returning no no not anytime soon sorry guys. Thats just Grandma Texas opinion.

This was really cool to see! We chose the easy 1 mile tour... I would reccomend doing the more in depth tour if able! We had our 2 year old daughter and 6 year old daughter... the 6 year old really enjoyed it the 2 year old not so much... so kid dependent might not be a thing to do with little ones! Super interesting! Deff reccomend!

Inner Space Caverns is a must for visitors and residents of the area! I’ve lived within miles of this place for 5 years and never visited until today; although I’ve wanted to for some time, I just wasn’t sure how kid friendly it’d be. Turns out, it really is great for all ages! My 11 year old niece really enjoyed it, as did my 5 year old and 21 month old daughters. My 5 year old was pretty nervous as we started making our way into the cave but Rachel was a fantastic tour guide! Rachel calmed her fears (And made the whole tour group laugh a lot!) and after about 15 minutes or so, my daughter told me how awesome everything was! I was also a little apprehensive about wearing a mask since it does get a little humid towards the end of the tour but it wasn’t bad at all, and you can take it off to catch your breath if you need to, so long as you distance yourself from others not in your group. This was such a unique experience!!

Great place to cool off from the Texas summer heat. Three choice of tours. The normal, tourista trip takes about an hour, or you can check out the new part of the caverns with flashlights for about 2. And you can even spelunk on the 4 hour grand tour!

This is an amazing tour. Our tour guide, Megan, had a good sense of humor and was very informative.

The tour was mildly informational. The cave was average with a couple interesting parts, but really humid.

That is BEAUTIFUL PLACE only the tour is to short

This was my second visit, and it was just as wonderful as the first. Going through a living system and seeing everything from the past and the present is just awe-inspiring!

We were amazed at this place. Did not expected to be so wonderful! We even wanted to try the intermediate tour!We did the basic guided tour with our girls and it was amazing! We are definitely coming back!

Since my first visit as a child in early 1970’s and many visits taking my son, and others - I have loved this living cave in Texas! Seeing the water marks change after flood seasons - the colors and formations are amazing and ever changing! Bling Blinky of Texas Shout Out: The quickest “Down Under” in Texas! Inner Space Caverns - historic experience for all!

Had a nice guided tour through a cavern that was discovered in1963 when the state was preparing to build interstate highway 35 through Georgetown, Texas.There were plenty of rooms along the tour with interesting formations. We saw a dragons foot, bacon and other interesting forms. Theyve also recovered sabertooth and other bones.I think the trip was nice because we also visited the nearby San Gabriel river and a little cemetery that was the site of the first African American high school in Georgetown.Our bus driver, Mark, was kind enough to take a slight detour to show us his hometowns pretty courthouse in Columbus.

Educational, Fun, worth the trip. Dress cool, prepare to sweat, its hot-n-humid, wet in most parts. 1hr. 15.min walk. They have others but theyre longer walks, (3hrs, 6hrs), that take you to parts of the cavern less traveled. 50 to 100 feet below surface. 28 for the one I took. If you get a great guide like I did, youll laugh all the way! He was amazing, very knowledgeable. Geologist major. Definitely Humorous!