What is the mystery of the Devil's Throat Cave?
Bulgaria's Devil's Throat Cave features a 42-meter underground waterfall that swallows everything in its path, never to resurface.
The Trigrad River plunges 42 meters into a cavern vast enough to hold a 12-story building, creating the tallest underground waterfall in the Balkans. Objects swept into its depths—logs, debris, anything caught in the current—vanish into a maze of tunnels and never reappear. The cave has captured imaginations for centuries; local legend claims it was the gateway to the underworld that the hero Orpheus himself descended through.
Nerd Mode
Devil's Throat Cave sits in Bulgaria's Rhodope Mountains near the village of Trigrad. Its main chamber, the Roaring Hall, spans 110 meters long and 40 meters wide. The waterfall drops 42 meters, making it the highest underground falls on the Balkan Peninsula. Over millions of years, the sheer force and volume of water have carved this massive subterranean space.The cave's true mystery lies in its drainage system. In 1968, a massive flood swept over 350 large pine logs into the cave. Not a single splinter was ever found at the river's exit several hundred meters downstream. This suggests the water travels through a series of natural siphons and narrow underground traps that act as a giant filter.Researchers have attempted to trace the water's path using specialized dyes. Although the dye eventually reaches the exit, it takes over two hours to travel a distance that should only take minutes by normal flow. This significant delay points to either an enormous, unexplored underground lake or a complex network of deep tunnels. The exact route remains unknown because high pressure and narrow passages make it too hazardous for divers to explore safely.
Verified Fact
FP-0002778 · Feb 17, 2026