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Inner Space Cavern Tours

4.4 2196 votes

4200 South IH 35

(512) 931-2283

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Just 24 miles North of Austin, Texas a natural cavern formed millions of years ago lies beneath one of Texas' busiest interstate highways.  Inner Space Cavern is filled with history, mystery and chemistry!  It's a living cave with spectacular displays of stalactites, helectites, soda straws, cave drapery and much more.

 More than 80,000 years in the making, Texas' newest and most-accessible cavern features spectacular rock formations and an unmistakable air of mystery. What kind of organisms began life in these caves? How did Mother Earth keep her underground secrets for so long?

From the moment you descend into the Cavern, you realize that the journey to find these answers will be just as important as the answers themselves. At a comfortable year-round temperature of 72 degrees, a paved walk way leads you through fascinating rooms filled with incredible rock formations. Stalactites and stalagmites surround you from every angle and formations such as the "Flowing Stone of Time" and the "Lake of the Moon" bring to life the pages of every history book you've ever read about the early days of our Earth. It is an experience you will not forget.

How was Inner Space Cavern Discovered

In the spring of 1963, a Texas Highway Department core drilling team was taking 6-inch core samples to determine if the ground was stable enough to support a large highway overpass (I-35) 24 miles north of downtown Austin. As they drilled one of the test holes, the drill bit suddenly dropped 26 feet and the crew knew something more was underneath their feet besides Texas rock. Several other test drills were performed in the area, and the large cavity was still found underneath. The crew supervisor decided to enlarge one of the holes to 24 inches and after drilling through 40 feet of solid limestone, finally broke into what is now Inner Space Cavern. One daring workman was lowered into the hole by standing on the drill bit and holding tightly to the stem--and became the first human being to enter Inner Space Cavern.  Don't miss out your opportunity to be next! 

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