Cenotes, Mexico

Like a giant block of Swiss cheese, Mexico’s Yucatan Peninsula is permeated with holes called cenotes. Cenotes form when subterranean limestone dissolves, allowing underground water to get through. The rock above may collapse, forming a pit and revealing the cool, often crystal-clear water, while other cenotes may remain hidden and unexplored. Cenotes vary in size from very small to several dozen metres across, and recent discoveries have shown that cenotes lead to a series of underground cave systems that can span several kilometres in length.
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