This was such a fun family filled day. This is a must see when you come to San Antonio!! It is amazing to see what is below the earth's surface! It's a whole new world under there! This is what we did Labor Day weekend and it was so beautiful. I didn't want to screw up all the details of the Natural Bridge Caverns and the discovery of it so I copied and pasted the info from their website. Also after they discovered the caverns the owners of the land try to give it to the government to preserve but the government didn't think it would be successful!! Another stupid choice by the government. Lets just say the land owners have millions due to this discovery, oh know Americans didn't need the money! Anyway it was so fun. Also finding out that most of Texas at one time was under warm shallow sea! This did make me very curious to what other wonders are lurking below us. Take time to read the info below to see how this amazing discovery of the caverns came to be! Hit the slide show to full screen and you can see the caverns better, Enjoy the Slideshow!
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 cavern 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.
Visitors to the caverns walk through different layers of limestone, a sedimentary rock. Geologists theorize that during the Cretaceous period, a warm, shallow sea covered much of Texas. Sediments and dead marine organisms collected on the ocean floor, compacted and formed the different limestone layers. Geologists give different names to the various layers, and visitors to Natural Bridge Caverns will find the Glen Rose and the Kainer (Edwards) layers. The Glen Rose, as the oldest rock layer, contains the lowermost chambers, while the Kainer forms the Natural Bridge.
Perhaps around 20 million years ago, a number of faults formed in Texas due to settling of the costal regions. These movements created an extensive series of faults known as the Balcones Fault Zone. The eroded face of the Balcones Escarpment marks both the fault zone and the beginning of the Texas Hill Country. In addition to creating the faults, the tectonic stresses also created joints, or cracks in the rock. Underground water moving along the joints eventually carved the passages at Natural Bridge Caverns, one of the main sources of San Antonio fun.
The cavern formed by an underground “river” moving slowly through cracks and pores within the limestone. Rainwater seeping through cracks started dissolving the limestone. In time, the original narrow cracks or joints enlarged to form huge underground conduits or passages.
Perhaps due to changes in climate, vegetation, or other natural forces, the water drained to lower levels within the earth. As the water left the upper passages, it moved deeper and started forming a second level. The water eventually moved to another level even deeper within the earth. As the water left the lower level, stresses within the rock led to many of the layers collapsing to form break-out domes. This final stage of collapse led to the creation of the passages our visitors now see.
