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

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)

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)

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)

A tourist splashes water on the frozen Songhua River on December 18, 2023 in Harbin, Heilongjiang Province of China. The water immediately freezes into ice in the frigid air. (Photo by VCG/VCG via Getty Images)

The artist Samantha French reveals the magnificent series of paintings: portraits of men and women under water. Very realistic creations expressing the world under water. Every detail is present, sunlight on water, air bubbles in the water, the color tone underwater, aquatic atmosphere. Absolutely amazing to discover in the rest of the article works.