A cooling tower is seen under mechanical demolition in Binzhou, Shandong Province, China, July 13, 2016. (Photo by Reuters/China Daily)

Cars drive under a rainbow near Bad Langensalza, Germany, Wednesday, November 2, 2016. (Photo by Jens Meyer/AP Photo)

A schoolgirl walks on an under-construction railway track at Navapura, on the outskirts of Ahmedabad, November 29, 2019. (Photo by Amit Dave/Reuters)

A woman whose family members are trapped under rubble wails after a landslide washed away houses in Raigad district, western Maharashtra state, India, Thursday, July 20, 2023. While some people are reported dead many others feared trapped under piles of debris. (Photo by Rafiq Maqbool/AP Photo)

People wash in water from a broken water pipeline on the outskirts of Kolkata, India, March 30, 2016. (Photo by Rupak De Chowdhuri/Reuters)

A cenote is a natural phenomenon, a sinkhole in the Earth’s surface. The Yucatan Peninsula in Mexico has an estimated 7,000 cenotes because it is primarily made up of porous limestone. For millions of years, rainfall slowly ate away at the limestone and a huge system of underground caves and caverns was formed. Many filled with water from rain or from the underground water table. When the roof of a water filled cave collapses, a cenote is born. The water found in a cenote may be fresh water, salt water, or both. Structurally it may be completely open, like a lake, almost completely closed with just a small opening at the top, or somewhere in between.

Vendors selling vegetables wait for customers under a flyover in the early morning in Ahmedabad, India on February 1, 2017. (Photo by Amit Dave/Reuters)

Multicolored nets are set under olive trees to collect the olives on November 27, 2013 in Castagniers, southeastern France. (Photo by Valery Hache/AFP Photo)