Mammoth Cave represents the largest cave system on earth that we know of. The system comprises multiple large caves and numerous tunnels. Even today, the full extent of the system remains unknown.
The numerous tunnels are still under exploration. To date, the total explored length of the tunnels exceeds 400 mi (640 km).
The cave system, located in North America, forms the centerpiece of the Mammoth Cave National Park in Kentucky, United States. This park contains the cave system itself, and most of the land above it. Further, as part of the park, the cave system also has the honor of being both a World Heritage Site and an International Biosphere Reserve.
Mammoth Cave Geological Formation
Mammoth Cave constitutes a rather incredible marvel of geology. In fact, it formed within limestone strata with a thick layer of sandstone caps, resulting in an extremely durable and stable formation.
The thick upper layer of sandstone itself has a riddling of countless narrow passages which, however, stay too narrow to enter.
Erosion created the entire system.
There are also several small rivers flowing through Mammoth Cave. Numerous stalactites and stalagmites are present at various locations throughout the cave system. One of the caves even connects to the surface by a recently formed sinkhole.
Mammoth Cave Biological Ecosystem
There are also a number of species of both animals and insects endemic to this cave. One of these is the extremely rare Kentucky cave shrimp which is a species of eyeless, albino, freshwater shrimp.
Other creatures include two types of crickets, two species of sightless fish, different salamanders, and a sightless crayfish.
Yet the most numerous are the several species of bats one of which is the now endangered Eastern Small-Footed Bat. In fact, Mammoth Cave was once home to an estimated 12 million of this species! Now, unfortunately, only a few thousand remain.
Additionally, many surface animals take refuge in the upper regions of the cave system.