In March of 1960, Orion Knox Jr., Preston Knodell, Al Brandt and Joe Cantu, four college students from St. Mary's University in San Antonio, obtained permission to explore the area that is now Natural Bridge Caverns. The students were convinced that large underground passages existed under the amazing 60-foot limestone bridge. On their fourth expedition, Orion felt a cool draft from a rubble-filled crawlway. Such air currents often indicate the presence of additional rooms or passages.
The explorers made their way carefully climbing and crawling through two miles of vast cavern passage. After making this amazing discovery, they returned to the surface to tell the landowners. The discoverers knew immediately what an astonishing find they had made and the land owners decided to develop the first 1/2 mile, the most spectacular part of the caverns, for the enjoyment of guests from around the world. That first 1/2 mile is now the Discovery Tour. Natural Bridge Caverns Discovery Tour was developed with two main goals in mind: preservation of the caverns' environment and comfort of its guests. The result is one of the world premier show caverns, and one of the most popular attractions in Texas.