The Cave of Swallows, also called Cave of the Swallows (Spanish: Sótano de las Golondrinas), is an open air pit cave in the Municipality of Aquismón, San Luis Potosí, Mexico. The elliptical mouth, on a slope of karst, is 49 by 62 m wide and is undercut around all its perimeter, further widening to a room approximately 303 by 135 meters (994 by 442 ft) wide. The floor of the cave is a 333 meter (1092 ft) freefall drop from the lowest side of the opening, with a 370 meter (1,214 ft) drop from the highest side, making it the largest known cave shaft in the world, the second deepest pit in Mexico and perhaps the 11th deepest in the world.[3] A skyscraper such as New York City's Chrysler Building could easily fit wholly within it.
History
Opened up by water erosion in a fault on an impermeable limestone plain and with a roughly conical shape, the cave has been known to the local Huastec people since ancient times. The first documented exploration was on 27 December 1966 by T. R. Evans, Charles Borland and Randy Sterns.
Etymology
The cave's Spanish name Sótano de las Golondrinas means Basement of the Swallows owing to the many birds which live in holes on the cave walls. These are mostly white-collared swifts (vencejos in Spanish) and green parakeets (periquillo quila).
Each morning, flocks of birds exit the cave by flying in circles, gaining height until they reach the opening and the sky. In the evenings a large flock of swifts circle the mouth of the cave and about once each minute, a group of perhaps fifty breaks off and heads straight down towards the opening.
When they cross the edge, the birds pull in their wings and free-fall, extending their wings and pulling out of the dive when they reach the heights of their nests.Watching this has become popular with tourists.
Post time 17-2-2014 03:06 PM
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