Day Trip to a Distant Past: Inner Space Caverns

Driving around Austin, there is so much to see to engage your imagination. Flashy neon signs, funky graffiti, natural parks.

But you may have missed one of the most natural beauties in the Austin area, just feet away. Seventy feet, to be exact, down below you as you pass along I-35 right outside of Georgetown.

The Inner Space Caverns were discovered in the 1960’s. Construction crews bore down while expanding the highway, only to realize that not only was their drill much deeper than they’d expected, but it was stuck! They drilled a 24″ hole nearby and lowered a man down to see exactly what was going on. Imagine drawing the short straw that day!

Discovery Cave, the first room the crew happened upon, is astonishing in its size and beauty. Walls of calcite are swirled with orange and pink coloration, a result of the iron in the adjacent Edwards limestone that works its way through the stone around it.

Native Species

Shaped by water, ancient ice floes and seismic activity from the Balcones Fault, the Inner Space Caverns are a gorgeous reminder of another time in Austin: an age of mammoths, saber-toothed tigers, enormous ground sloths and the ancestor of the Texas armadillo!

Though lots of bones and tusks have been discovered in the caves, the thick, clay-like mud on the cavern floor has made recovery difficult. It’s easy to see things like fossilized coral and prehistoric shrimp burrows in the ceiling, though. (You’ll be glad to know that no prehistoric shrimp are served in the café.) The caves used to be filled with huge prehistoric bats, too! The current residents are the teeny tiny tri-color bats. If you’re lucky, you can see one sleeping during your tour!

The rock formations make the cave tour worth it. Each spire represents about 100 years of growth for each cubic inch. The exploration aspect of the tour is a great draw for kids, making one feel like an intrepid archaeologist peering into each nook and cranny!

Extra Explorers Tour

We decided to pay $2 extra a person to do the Explorers Tour. It gave us the opportunity to grab flashlights and explore deeper areas of the caverns on our own. It was so exhilarating and spooky, and I might have started humming the X-Files theme song.

What a sense of perspective, too! One formation of rock was called the Lunar Field by the original cave excavators in the 1960’s, before anyone had ever BEEN to the moon. So intricate and mysterious, these formations inspired visions of what space must look like. Once someone went to the moon, however, they realized that “Lunar Field” needed to be renamed. The moon was just not as cool-looking.

Tips for Your Inner Space Caverns Experience

• Wear shoes with good treads. The cave floors can sometimes be slippery. They’re lit, but still dark, so make sure you can get good footing. You’ll be walking about a mile underground.
• Dress in layers. No matter how chilly it is above ground, the caves are pretty warm and constant at 98% humidity. You won’t need your coat/scarf/hat.
• Bring your camera! The caverns are absolutely BEAUTIFUL and specific rock formations have been lit for your photographing pleasure! Lots of the “rock” around you is crystalline. Photographs stunningly reflect light and color that you wouldn’t expect.
• Bring the family! We absolutely loved the adventure of Inner Space Caverns, and the kids on our tour were transfixed with delight. It was an active tour, full of science and history and natural wonder. Kids under 6 might have trouble with the terrain.

There is apparently a “Wild Cavern” tour that we’re really hoping to try out in the future. It includes serious cave climbing and is a lot more rigorous. It happens only on Saturdays and needs to be booked in advance. For the standard adventurers, though, the regular daily tours provide a satisfying taste of history and natural wonder, hiding below Interstate 35!

Plan your trip at MyInnerSpaceCavern.com.