the bottom of the cave has the size of 3 football fields?
Placed in the township of Aquismón included in the Mexican province of San Luis Potosi, is one of world's deepest alfresco pit caves, the Sótano de las Golondrinas, also known as the Cave of Swallows. With a depth of approximately 380 meters and diameter of about 60 meters at the top and 300 meters at the bottom, it is counted as worldwide largest and Mexico's second deepest cavity. In fact, it is so deep that it can swallow one full skyscraper of New York City, no wonder it got that moniker, although history holds a different reason.
The temperature is considerably low inside the cave where rarely you will find any vegetation. The mouth, however, is covered with a natural green carpet of rich vegetation, thanks to the rain and sunlight its gets. The water from this rain cascades down to the depth of the cave where heavy deposits of debris, guano and wild fauna like insects, millipedes, scorpions and snakes are found. Created by the forces of erosion, this cave has been known to people since a very long time, but only recently has it received the recognition as a great tourist spot.