The cave is around 365 miles and is the largest cave to be explored so far.
The cave is made up of limestone, sandstone, and shale cap. with the caves being so large, you would think there would be more accidents but there are surprisingly only a couple since the tours started.
Fun fact: jack has been to mammoth caves and is in a large group picture on it's website.
The caves have rivers and sinkholes in them. There are plenty of animals around the caves including bats, fish,and shrimp of various kinds. There are actually boat tours you can take throughout some of the caves. One of the most popular boat tours was the Echo River Tour. The Echo River Tour was unfortunately closed because of environmental reasons. The Lost River Cave Tour which I believe is still open is or was one of the most popular as well. There are actually about 130 species of animals that use the caves for shelter and recourses. There are 12 species of eyeless animals that live in the caves which I find weird and interesting.