A polar bear fast asleep at London Zoo. (Photo by Fox Photos/Getty Images). 1961

Two children jumping through a water hydrant's shower on a New York street. They have come from a neighbouring co-educational playgroup organised by the city's Police Department. (Photo by Orlando/Getty Images). 1950

Marianne Brauns jumping a breakwater on the beach, wearing a structured blue swimsuit with white trim. (Photo by Carl Sutton/Hulton Archive/Getty Images). Circa 1950

North Korean girls in similar bathing suits stand under a shower at the Songdowon International Children's Camp, Tuesday, July 29, 2014, in Wonsan, North Korea. The camp, which has been operating for nearly 30 years, was originally intended mainly to deepen relations with friendly countries in the Communist or non-aligned world. But officials say they are willing to accept youth from anywhere – even the United States. (Photo by Wong Maye-E/AP Photo)

A woman leans against one of the stones of the Stonehenge monument on the summer solstice near Amesbury, Britain on June 21, 2017. The annual festival attracts hundreds of people to the 5000 year old stone circle to mark the longest day in the northern hemisphere. sunrise was at 4.52am and was celebrated by dancing, music, and ritualistic events around the stones. (Photo by Neil Hall/Reuters)

Hot Tub Cinema is an experience like no other. Combining relaxing hot tubs, great films and amazing spaces, it is a luxurious event that celebrates film in a fun and engaging way. Attendees can purchase whole tubs to share with friends or buy individual tickets to share with fellow hot tubbers. The tubs are cleaned, refilled and heated before every show. Popping-up throughout the year in London and around the UK, Hot Tub Cinema is also preparing to tour internationally in the near future. During the summer, we takeover rooftops in central London with astounding views across the city's inimitable skyline. For the autumn/winter we move indoors to continue the fun hidden away from the unpredictable weather.

A instructor (2nd L) from the Philippine Mermaid Swimming Academy assists participants of a monofin swimming summer workshop as they practise floating in the water of a private pool in Paranaque city, metro Manila April 5, 2014. The Philippine Mermaid Swimming Academy workshops, which were originally conducted on the beaches of Boracay Island, central Philippines, currently cost 1,800 pesos per person ($40) for a two-hour session. (Photo by Romeo Ranoco/Reuters)

These incredible pictures look like a bird's-eye view of a faraway alien planet – but they're actually hot springs. The amazing snaps are up-close shots of Iceland's hot springs, and the point-blank pictures produce a breathtaking array of colors and effects. Here: The amazing snaps are up-close shots of Icelandic hot springs. (Photo by Johann Vilhjalmsson/Caters News)