This is not an abstract and the colors are from lights in the cave.
I A Overview:
Yes, some say that Mark Twain Cave in Hannibal, Missouri has a small chamber that is chilly and icy. One description from a brochure says the chamber has limestone walls that are "dewy with cold sweat". Another review from May 2023 mentions glacial deposits that line the cave's floors.
The cave is open year-round and is kept at a constant 52°F. It's also one of the few labyrinth-style caves in the world and is a registered National Natural Landmark. The cave is unique because it doesn't have stalactites or stalagmites, but instead its limestone walls are covered with hundreds of thousands of signatures.
Ian