Inner Space cavern was discovered by a Texas Highway Department core drilling team in the Spring of 1963. Six inch core samples were taken to determine if the ground was stable enough to support a large highway overpass. As they were drilling one of the test holes, the bit suddenly dropped 26ft. and the highway crew knew there was something down there besides rock.
After drilling through 40 feet of solid limestone, the bit broke into what is now known as Inner Space Cavern.
News of this fantastic discovery spread fast and within the next few months, the Texas Speleological Society had secured permission to enter and explore the dark reaches of the newly discovered cave. The first group of spelunkers entered the cave on a cool November morning in 1963. A wooden tripod was erected over the core hole, and each person was lowered down the narrow shaft on a rope tied to an automobile.
Within the next several days, over 7,000 feet of cave had been surveyed. The passages varied from very tight crawls to large cathedral-type rooms and halls. For the most part the cave was easy going except for a few tight tunnels and the sticky mud that exists in all parts of the cave.
Inner Space was opened to the public in the summer of 1966, and since that time hundreds of thousands of visitors have seen this beautiful cave.