A girl walks along rice paddy fields during “National Paddy Day”, which marks the start of the annual rice planting season, in Tokha village on the outskirts of Kathmandu on June 29, 2020. Splashing mud and drinking local rice beer, Nepali farmers this week celebrated National Paddy Day to mark the beginning of the rice-planting season, despite some coronavirus lockdown measures still in place. Traditional farming songs and laughter echoed in the air as farmers waded into waterlogged fields to sow green paddy. (Photo by Prakash Mathema/AFP Photo)

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.

Sunrise over the fields of stemmy grassland in Burscough, Lancashire, UK on September 14, 2020 with wrapped bales of hay prepared for silage, haylage for animal winter feed. (Photo by MediaWorldImages/Alamy Live News)

Giving out with a yell, Elke Sommer is tossed on the trampoline as she trains for her movie role as an athlete, on the playing field of the University of California at Los Angeles, June 8, 1967. (Photo by AP Photo)

Workers tend green onion plants among nearly 1,000 acres of terracing in fields in the Majalengka Regency of West Java in Indonesia in July 2021. (Photo by Andika Oky Arisandi/Solent News)

Bangladeshi farmers carry harvested produce in a cultivated field ahead of the 14 May World Farmers Day in Chittagong, Bangladesh on May 12, 2022. (Photo by Mohammad Shajahan/Anadolu Agency via Getty Images)

A young woman dances in a field of tulips in a park in central Moscow on May 10, 2019. Moscow enjoys a heatwave while the rest of Europe struggles with cold weather. (Photo by Mladen Antonov/AFP Photo)

This photo taken on February 26, 2019 shows an aerial view of a tea field in Zhangping in China's eastern Fujian province. (Photo by AFP Photo/China Stringer Network)