Caves are one of the spookiest places on Earth. Most of the time these dark and mysterious caverns are dangerous to explore. Over the years, many cave systems on our planet have amassed a collection of strange phenomena that we have only discovered recently.

In this video, we’ll explore some of the most exciting caves in the world, where the weirdest things have been discovered.

From the oldest human footprints in the world to the cave of our cannibal ancestors, here are the 15 strangest things found in caves.