The Caverns of Sonora, a National Natural Landmark, is a unique cave located 8 miles (13 km) west of the small city of Sonora, the seat of Sutton County, Texas. It is a world-class cave because of its stunning array of calcite crystal formations, especially helictites. These helictites are found in extreme abundance, often with a rare purity and complexity. One formation is so densely packed with them, it has been dubbed the "snake pit".