A Natural Gas

My wife and I knew that the Hill Country of Texas, and particularly the area around New Braunfels, San Antonio, San Marcos, and Austin was literally pock marked with caves and caverns.

We knew that out of the 3,000 or so caves, clefts, caverns, and sinkholes in the state, most of them were in that area, and we knew they were very well visited by many persons. We decided t...