Natural Bridge Caverns

Four St. Mary's University students found it on March 27, 1960, and what they found was the largest commercial cavern in Texas. The name comes from the 60-foot limestone slab bridge spanning the entrance — a span left hanging when a sinkhole collapsed beneath it. The temperature inside holds at 70°F year-round. The deepest public tour reaches 180 feet below the surface. It opened July 3, 1964, and has been family-owned and operated ever since. In 1971 it became a registered US National Natural Landmark.