The Cave of Swallows in Mexico is the largest known cave shaft in the world.
This giant sinkhole is 200 foot wide and an amazing 1,220 feet deep just in the middle of the Mexican jungle.
El Sótano de las Golondrinas – The Cave of Swallows – is so deep that clouds form inside it.
The cave’s total depth is 1,638ft with the final few hundred feet accessible via a pit series called The Crevice.
It is believed that the sinkhole formed from the collapse of the roof of an underground cave, which in turn was formed by water erosion along a fault line in the limestone.
Flocks of green parakeets and white-collared swifts leave the cave each day, circling up the shaft before pouring out into the surrounding jungle. This is the origin of the cave’s name: El Sótano de las Golondrinas, (Cave of Swallows).
A hot air balloon was once navigated through the 160-foot wide opening, landing on the floor below.
The cave used to be popular with BASE jumpers, but ornithological studies have found that the bird population of El Sótano de las Golondrinas is decreasing. Now BASE jumping is no longer permitted.