Just 24 miles to the north of Austin, Texas, lies a natural cavern that was formed millions of years ago, hidden beneath one of the busiest interstate highways in the state. Inner Space Cavern offers a captivating blend of history, mystery, and geological wonders. As a living cave, it showcases breathtaking displays of stalactites, helictites, soda straws, cave drapery, and much more.
This remarkable cavern, which took over 80,000 years to develop, stands as Texas’ newest and most accessible underground marvel. Its magnificent rock formations and an aura of enigma make it truly unique. Contemplating the organisms that once inhabited these caves and the secrets that Mother Earth has guarded for so long, you embark on a journey to uncover the answers.
Descending into the cavern, you quickly realize that the quest for knowledge is as significant as the knowledge itself. The walkway, smoothly paved and maintained at a comfortable temperature of 72 degrees year-round, guides you through captivating chambers adorned with awe-inspiring rock formations.
Stalactites and stalagmites surround you from every angle, while formations like the “Flowing Stone of Time” and the “Lake of the Moon” breathe life into the pages of ancient history books. This experience is one that will etch itself in your memory forever.
Discovery of Inner Space Cavern
In the spring of 1963, a team from the Texas Highway Department was conducting 6-inch core sample drilling to assess the stability of the ground for constructing a large highway overpass on I-35, located 24 miles north of downtown Austin. As they drilled one of the test holes, the drill bit unexpectedly plummeted 26 feet, revealing the existence of something more than just Texas rock beneath their feet.
Several subsequent test drills confirmed the presence of a significant cavity in the area. The supervisor of the crew made the decision to enlarge one of the holes to 24 inches. After penetrating 40 feet of solid limestone, they finally broke through into what we now know as Inner Space Cavern. A courageous worker descended into the hole by standing on the drill bit and grasping the stem, thus becoming the first human to set foot inside Inner Space Cavern. Don’t miss your chance to be the next to explore this extraordinary place!
Inner Space Cavern Tours Gallery
Inner Space Cavern Map
- Address: 4200 South IH 35
- Call: (512) 931-2283
- Website: https://innerspacecavern.com/

Newsofaustin.com is a travel website founded by Ralph C. Wachter, an avid traveler who wanted to share his passion with the world. He created a collection of comprehensive travel guides to help fellow travelers plan their trips with ease. As the website gained popularity, Ralph assembled a team of experienced freelance travel enthusiasts and editors to maintain the quality of the content.
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