Boybuloq Cave
The cave is the deepest known cave in Asia having been explored to a depth of from the entrance. At the lowest discovered level a water-filled siphon blocks further exploration. It is thought that the cave has the potential to be the deepest known cave in the world, with a theorised depth of making it deeper than the Veryovkina Cave. The explored length of the cave is .
Indian Caverns
Indian Caverns was a show cave in Spruce Creek, Pennsylvania, United States from 1929-2017. It is a horizontal karst cave of Ordovician Nealmont/Benner limestone, estimated to be about 500,000 years old. It is the second-largest cave in Pennsylvania and the largest limestone cave. Indian Caverns consists of two sections, originally separated by a 14-foot wall: the "Historic Cave" and the "Giant's Hall". The "historic" part of the cave is generally low-ceilinged and closer to the surface (as shallow as 15 ft) with a couple of wide rooms and extensive speleothem formation. The Giant's Hall area consists of several large passageways, up to 60 feet high, but with fewer speleothems - though it does include the largest sheet of flowstone in the northeast and a substantial rimstone pool. The lowest point of the cave is approximately 140 feet beneath the surface and the cave temperature is a constant 56 degrees Fahrenheit (13 degrees Celsius).