The Devil's Kitchen
Found along the Soldier Pass hiking trail in Sedona, Ariz., the Devil's Kitchen sinkhole gets its sinister name from its red walls, which are made of sandstone. It reportedly first collapsed in the early 1880s, with a second historical collapse in 1989. The relatively young sinkhole's features are so angular because the surfaces of its rocks' edges have not yet been sloughed dull. The large rectangular rock toward the center is known as the Grand Piano.
House of the Demon
Here's another view of the Bimmah Sinkhole, which was created when a limestone cavern collapsed. However, local folklore states that a chunk of the moon fell from the sky and formed the hole when it hit Earth. Residents refer to the sinkhole as "Bait al Afreet," or the "House of the Demon," although with its tranquil azure waters, it looks quite heavenly.
The Bimmah Sinkhole is near Dibab village in Oman, an Arab state in the Arabian Peninsula. A winding stone staircase leads down to the sinkhole, which is a beautiful aquamarine and emerald color, with the darker green hues resulting from algae growth in the water.
Pictured above is what's known as a "blue hole," or an underwater sinkhole, located in the Lost River Cave and Valley of Bowling Green, Ky. The result of an underground, dissolved limestone drainage system that rests beneath the region, the blue hole is surrounded by local myths of swimmers disappearing below its murky, stagnant surface, never to return. [Gallery: Lost in the Bermuda Triangle]
Located in Green County, east of Bowling Green, Ky., this sinkhole formed about eight years ago; the owners of the farmland where it formed have since pushed old hay rolls into the hole, where a tree has already begun to grow. The walls of the sinkhole are a rich, rusty color, characteristic of the reddish-brown colored silt and dark red clay of central Kentucky's soil.
The photographer snapped this aerial photo of the Melchor de Mencos sinkholes while flying over Petén, in the northern part of Guatemala. These twin cenotes are located near Lake Macanche and are surrounded by a thick rain forest.