Devil's Sinkhole State Natural Area

Devil's Sinkhole State Natural Area is a 1,859.7 acres (753 ha) nature reserve with a natural bat habitat in Edwards County, Texas, United States managed by the Texas Parks and Wildlife Department. The sinkhole is a 350-foot deep cavern with a roughly 50-by-140-foot (15.2 m × 42.7 m) opening at the surface. It is Texas' largest single-chambered cave and home to up to three million Mexican free-tailed bats between the months of April through October.

Park data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).