Inner Space Cavern is one of the most interesting geological and historical attractions in Central Texas — and one of the most underrated. Discovered in 1963 when highway crews drilling for I-35 broke through into a pristine cave system beneath Georgetown, the cavern has been welcoming visitors for over six decades.
The Discovery Story
The cavern's discovery is part of its appeal. Drilling equipment punched through the limestone ceiling in 1963, and what the construction crew found was a pristine, undisturbed cave system formed over millions of years. The decision to preserve and open it to the public rather than build over it was a fortunate one — today it stands as one of Texas's best-preserved show caves.
What You'll See
Guided tours walk through the cave's chambers past spectacular stalactite and stalagmite formations, underground lakes, and the fossilized remains of prehistoric animals — including mammoths and saber-toothed tigers whose bones were preserved in the cave for thousands of years. The constant 72-degree cave temperature makes it a refreshing escape during Central Texas summers.
Visiting Information
Inner Space Cavern is located at 4200 S I-35 in Georgetown — right off the highway and easy to find. Tours run daily from 9am to 5pm. The cave is accessible from the Georgetown and Round Rock exits on I-35. After your visit, the Georgetown square is just a few minutes away — stop at Monument Café for lunch on the historic downtown square.