This aerial view shows youths swimming to cool off in the waters of Iraq's Euphrates river during a heatwave, in the district of al-Hindiyah east of Karbala on June 7, 2024. (Photo by Karar Jabbar/AFP Photo)

A swimmer stops short of a red algae bloom at Sydney's Clovelly Beach on November 27, 2012, which closed some beaches for swimming including Bondi Beach for a period of time. While the red algae, known as Noctiluca scintillans or sea sparkle, has no toxic effects, people are still advised to avoid swimming in areas with discoloured water because the algae, which can be high in ammonia, can cause skin irritation. (Photo by William West/AFP Photo)

Will Rosner and a playful humpback whale pose for a selfie. This man is certainly knows how to enjoy life travelling the South Pacific and posing for selfies with a whale. Australian carpenter Will Rosner, 24, from Sydney, Australia, has been travelling the world for the past 18 months but nothing could have prepared him for this incredible postcard moment. Swimming in the pristine waters of the Tonga in the Pacific Ocean Will was lucky enough to have the chance to swim with an entire pod of humpback whales. (Photo by WIll Rosner/Caters News)

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.

An athlete dressed as a clown jumps into the Mediterranean sea as he takes part in the Copa Nadal in the Spanish port of Barcelona in Barcelona, Spain, Sunday, December 25, 2016. The Copa Nadal (Christmas Cup) is a traditional swimming competition that takes place in Barcelona every December 25th, where participants swim 200 meters in the open sea in the port of Barcelona. (Photo by Manu Fernandez/AP Photo)

A man wearing a water-filled helmet in which a goldfish swims performs an act titled “Aquaman” during the Night Festival 2016 in Singapore, 20 August 2016. The ninth edition of the festival will run from 19 to 27 August and features installations and performances by a range of international and local artists. (Photo by Wallace Woon/EPA)

A boy swims in Chao Phraya River as he helps to place a Krathong, or a “floating basket”, in the water amid a yearly festival during which rafts of neatly folded banana leaves, decorated with flowers, candles and incense, are offered to thank the water goddess for good luck and for using her water to grow crops and support all life, in Bangkok, Thailand on November 8, 2022. (Photo by Chalinee Thirasupa/Reuters)

Norway's Casper Ruud jumps in a swimming pool after winning the Barcelona Open in the final match against Greece's Stefanos Tsitsipas in Barcelona, Spain, on April 21, 2024. (Photo by Albert Gea/Reuters)