On the west side of Camp Bullis, at the edge of the Dominion neighborhood, Rustin Tabor pulls his truck to the side of a winding road and walks a few feet into the wooded area that lines it.

Farther in, stretched across the dirt, is an entrance to a cave — a karst that leads deep under the forest to the Edwards Aquifer. A grate has been installed on the opening to prevent anyone from climbing down into it.

Read more from Elena Bruess with San Antonio Express-News here.