Subterranean waterfall

Subterranean waterfall or cave waterfall, also called an underground waterfall or waterfall cavern is a waterfall located underground and may be in a cave. Subterranean waterfalls may be under or above sea level. A renowned example is Ruby Falls located in Lookout Mountain Caverns in Tennessee, United States and is one of largest and deepest waterfalls in the United States.

Cavernous waterfalls exist throughout the world including Gaping Gill cavern in North Yorkshire, United Kingdom. The tallest known cave waterfall, in Vrtoglavica Cave in Slovenia, is at least 400 m.