In 1963 while building Interstate 35 through Georgetown Texas, the Texas Highway department lost 17 drill bits while drilling into the earths surface. As a means of trying to understand where the drill bits went, they sent down their youngest and smallest employee who was age 19, into a hole 20" in diameter. The young employee then dropped into the darkness 17 feet to the floor of what is now known as the "Inner Space Cavern." How spooky must that have been for this young man..... But how totally Awesome too..