The Blue Hole near Dahab, Egypt, in the Gulf of Aqaba is one of the most dangerous underwater caves in the world. The cave is explored daily by adventurers but these divers found more than they were bargaining for in the Blue Hole.

The following video was shot by a pair of divers exploring the Blue Hole in late 2006. At around the 360-foot mark, they came across the badly decomposed body of an unknown diver. No one is quite sure who it was and how they ended up dead at the bottom of the cave system. Reguardless of what happened to the diver, it had to have been an unpleasant death. A heartbreaking and terrifying sight indeed.

WARNING: the following footage is not for the faint of heart.

Sadly, the divers who spotted the body were not able to bring it up to the surface with them. As far as we can tell, the body was never retrieved and at that depth maybe never will be. R.I.P., mystery diver. And to those considering attempting challenging dives without guides, let this unknown diver be a warning to you.