Members Only Area
Bookmark and Share
sidebar menu icon


NATURAL BRIDGE CAVERNS. Natural Bridge Caverns, the largest known cavern in Texas, was discovered on March 27, 1960, by four spelunkers who were students at St. Mary's University in San Antonio. The cavern is located off Farm Road 1863 in the hill country of Comal County midway between New Braunfels and San Antonio (at 29°41' N, 98°21' W). The name was derived from the sixty-foot natural limestone slab bridge that spanned the amphitheater setting of the cavern's entrance.

Commercial development of the cavern began on March 25, 1962, and it was opened to the public on July 3, 1964. During excavation of the entrance trail, arrowheads and spearheads dating from 5,000 B.C. were found; just inside the entrance were discovered jawbones of a species of grizzly bear that became extinct over 8,000 years ago. The cavern is almost 100 percent active and still growing, and the temperature is seventy degrees year-round. Because of constant drips and flowing water, the formations retain a luster that can be seen in few caverns. Under these growth conditions the formations appear to be made of wax, yet are as hard as limestone. The types of formation change from room to room. The largest room, named the Hall of the Mountain Kings, is 350 feet long, 100 feet wide, and 100 feet high. Among numerous formations found here the most distinct is a type called "fried eggs" (because that is what they look like), a rare cave formation. The developed portion of the cave, furnished with a half mile of paved trails and illuminated by 35,000 watts of indirect lighting, extends to as much as 260 feet below ground level. Some portions of the cave are still under exploration. Natural Bridge Caverns became a registered United States natural landmark in 1971.

Clara Heidemann

Image Use Disclaimer

All copyrighted materials included within the Handbook of Texas Online are in accordance with Title 17 U.S.C. Section 107 related to Copyright and “Fair Use” for Non-Profit educational institutions, which permits the Texas State Historical Association (TSHA), to utilize copyrighted materials to further scholarship, education, and inform the public. The TSHA makes every effort to conform to the principles of fair use and to comply with copyright law.

For more information go to:

If you wish to use copyrighted material from this site for purposes of your own that go beyond fair use, you must obtain permission from the copyright owner.


The following, adapted from the Chicago Manual of Style, 15th edition, is the preferred citation for this article.

Clara Heidemann, "NATURAL BRIDGE CAVERNS," Handbook of Texas Online (, accessed December 01, 2015. Uploaded on June 15, 2010. Published by the Texas State Historical Association.