World's Greatest Swimming Pools: Four Seasons, Serengeti Pool, Tanzania. A show of elephants, buffalo and baboons awaits thanks to an active watering hole below the free-form infinity pool at this plush hideaway inside Serengeti National Park. Bonus: Because of infrared technology at the hole, guests can be notified on their bedroom TV when animals are approaching. When you've got word of wildlife on the horizon, catch them from your private terrace – or head back to the pool. (From $1,650). (Photo by Four Seasons)

The team from France performs their Free Routine during the Synchronized Swimming Olympic Games Qualification Tournament at the Maria Lenk Aquatics Center in Rio de Janeiro, Brazil on March 6, 2016. The tournament is also a test event for the Rio 2016 Olympics. (Photo by Sergio Moraes/Reuters)

A swimmer reacts after finishing his competition in a pool carved into thick ice covering the Songhua River during the Harbin Ice Swimming Competition in the northern city of Harbin, Heilongjiang province January 5, 2015. The swimming competition was held on the official launch day of the Harbin International Ice and Snow Sculpture Festival. (Photo by Kim Kyung-Hoon/Reuters)

These talented turtles have been "snapped" performing for the camera as they practice their synchronized swimming routine. Photographed underwater by Monste Grillo, 36, from Tenerife, Spain, the turtles are seen swimming in unison as well as touching fins as they circle towards the surface. After spending hours in the water off the coast of the Canary Islands in 2012, the photographs capture the gentle nature of the creatures as well as giving a fascinating glimpse into their behavior in the wild. (CATERS NEWS)

Swimmers climb out of a pool carved into the thick ice covering the Songhua River during the Harbin Ice Swimming Competition in the northern city of Harbin, Heilongjiang province January 5, 2014. According to organisers, about 700 swimmers across China took part in the event on the official launch day of the Harbin Ice and Snow Sculpture Festival. (Photo by Kim Kyung-Hoon/Reuters)

Talini (R), a 9-month old 160-pound polar bear cub, swims with her mother Barle at the Detroit Zoo's Artic Ring of Life exhibit August 25, 2005 in Royal Oak, Michigan. Talini's birth was the first polar bear birth at the Detroit Zoo in fifteen years. Her mother Barle was wild born and was rescued by the Detroit Zoo from a circus in Puerto Rico in 2002. (Photo by Bill Pugliano/Getty Images)

Brazil's synchronised swimmers Luisa Borges (front) and Maria Eduarda Miccuci perform during a training session at the Rio Olympic Park in Rio de Janeiro, Brazil, April 7, 2016. (Photo by Pilar Olivares/Reuters)

Visitors watch as Grigory Broverman, a member of the Cryophile winter swimmers club, pours a bucket of cold water over his 6-year-old daughter Liza during a flash mob, part of a celebration of Polar Bear Day at the Royev Ruchey Zoo in a suburb of the Siberian city of Krasnoyarsk, Russia, November 29, 2015. The air temperature was around minus 5 degrees Celsius. (Photo by Ilya Naymushin/Reuters)