A boy plays at a flooded street in front of a passing bus as tropical storm Fung-Wong battered the Philippine capital Manila September 19, 2014. Heavy rain in the Philippine capital, Manila, caused flooding in many areas on Friday, shutting schools, government offices and financial markets as a tropical storm made landfall to the north. Thousands of residents in low-lying areas were moved to higher ground, officials said, as flood waters rose quickly after the equivalent of half a month's usual rain fell in six hours. (Photo by Erik De Castro/Reuters)

A Kashmiri Muslim woman balances on a water pipe before collecting water at Dasilpora village on March 22, 2018. World Water Day is held annually on 22 March as a means of focusing attention on the importance of freshwater and advocating for the sustainable management of freshwater resources. (Photo by Tauseef Mustafa/AFP 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.

People play "Palin", a traditional ritual and ancestral Mapuche game played with curved sticks called "Chuecas" and a wooden ball, during a meet on Dia de la Raza (Day of the Races), also known as Columbus Day in Vina del Mar, Chile October 11, 2015. (Photo by Rodrigo Garrido/Reuters)

Local actor Colin Retallick plays the role of St. Piran during the annual processional play to celebrate St. Piran, patron saint of tinners and regarded by many as Cornwall's premier saint, on March 4, 2012 in Perranporth, England. (Photo by Matt Cardy/Getty Images)

As Russia puts the finishing touches to the carefully manicured fields that will host the World Cup from next week, people around the globe are playing soccer on a surprising variety of makeshift pitches. Off the coast of an island in southern Thailand, they play on a floating platform; in the mountains of northern Italy, they kick about in the snow – images captured by Reuters photographers around the world. Here: Local residents play soccer on the top floor of a parking garage in Jakarta, Indonesia, May 4, 2018. (Photo by Darren Whiteside/Reuters)

An actor holds a fake baby while waiting for the Wintershall Nativity play dress rehearsal to begin at Wintersall Estate on December 12, 2021 in Guildford, England. The Nativity play, which tells the story of the birth of Jesus Christ, has been performed annually since 1990 over the Christmas period by the Wintershall players. (Photo by Hollie Adams/Getty Images)