There are plenty of reasons why many of us avoid caves. Not only are caves incredibly dark, but they can also get unbelievably cramped. There is a lot of uncharted territory in cave exploration, and it triggers a sense of dread and discomfort in most people.

With these discoveries, it seems like there are more reasons to avoid caves. Let’s take a look at the most horrifying things discovered in caves from all around the world.

From one of the biggest bat caves in the world, to a toxic cave, here are the 15 scary things found in caves.