Inner Space Cavern, located just north of Austin in Georgetown, was discovered in 1963 after being hidden for over 14,000 years. During the construction of highway 35 the Department of Transportation was taking core samples and drilling through 40 feet of limestone when the core samples came up empty after 40 feet. Meaning there is a big open hole down below the surface. A brave DOT employee was lowered into the hole standing on the drill bit and holding onto the drill stem. I can only imagine the excitement that he must have experienced and the "WOWs" that the crew above must have heard from that small hole in the ground. During the tour you can see where he entered the cave.
But DOT employees were not the first to discover this natural wonder - over millions of years prehistoric animals found the cave either accidentally by falling in or on purpose in search of food or water. Once in the the deep cavern, few escaped and others drowned in thick quicksand like mud at the bottom of watering holes. Because of that, Inner Space Cavern is one of few caves in Texas where skeletons of prehistoric Ice-Age animals were found and excavated. Some of the skeletons included: saber-toothed cat, glyptodont (a Volkswagen-sized armadillo), camel, horse, ground sloth, short-faced bear, peccary, bat, and other species. During the tour you'll see a pictograph of some of those animals that were discovered, view several bones, and see one of the archeological dig sites.
The caverns were carved by water passing through Edwards limestone and they are are estimated to be 90–100 million years old but were only open to the surface since the late Pleistocene period 20,000–45,000 years ago, which is evidenced by finds of mammoth and sabre-toothed cat bones. All natural entrances closed approximately 14,000 years ago. In 1966, a new entrance was blasted into the cavern and Inner Space Caverns began giving tours to the public. Over five miles of trails have been explored but less than 2 miles of that is open for public exploration. Click here to see a map of the Inner Space Cavern.
Inner Space Cavern offers three different tours:
With our three grandkids, aged 3 to 6, we signed up for the Adventure Tour on a hot summer day in July. I was a little reluctant to take three young kids on a 75 minute tour - they all have very short attention spans, are rambunctious and adventurous, talkers and not listeners, and are just like most other kids in that age group. But they were fantastic, awe struck, attentive, and loved it - they are still telling their moms and dads about their first cave adventure!
You start the tour by boarding a 15 to 20 person cable car and heading down a fairly steep slope to the entrance to the cave - this and the ride back up was the youngest grandkid's favorite part! At the bottom of the cable car ride you're in the cave and for the next 75 minutes or so you walk along a paved walkway that twists and turns it's way deeper into the cavern, past some interesting formations, through tunnels where you need to watch your head and into huge open caverns.
Our tour guide was great and every two to five minutes we stopped and learned about the cavern, the formations, the prehistoric animals, and lots more. The grandkids also loved the part where the tour guide wouldnask everyone to be quiet and then she turned out the lights! That's dark! We couldn't see anything including our hands right in front of our noses!
We learned about stalagtites, stalagmites, helictites, ancient flowstones; saw some prehistoric bones and one of the excavation sites; walked past one of the original entrances to the cave; watched several bats hanging on the wall checking out the tourists; came up with names for our special geological formations like "Monster Man," "Hanging icicle," "Dripping Straw," and more; and we could easily see why some of nature's artwork was called "The Flowing Stone of Time," the mysterious "Lake of the Moon," and the stunning "Soda Straw Balcony," and what looked like a tasty "Ice Cream Cone," all of which have been growing for thousands of years. Our guide was very interesting and informative, personable, invited questions, and knew all the answers to our myriad of questions. A fun and entertaining tour.
Before or after your tour you can pan for real gems and minerals just like the old time miners did - you'll buy a sift bag and run it through Inner Space Cavern's sluice and discover genuine gemstones. The gift shop is loaded with mine and cave related souvenirs as well as lots of other stuff to spend your money on. As you wait for your cable car, peruse the walls to learn more about the cave and check out the cave map. You might consider loading up on snacks and drinks before you head deep into the heart of the cavern - if the lights go out you'll have plenty of calories to keep you going. Don't worry, that will never happen, there are redundant systems to ensure that the lights never go off.
Make sure you check out Texas Outside's Caving Page to find other Texas caves to explore and enjoy. And if you enjoy caving, read our article on our unique and adventurous cave tour at the Caverns at Sonora.