The Y-40 Deep Joy is the worlds deepest pool. Y-40 is projected by Architect Emanuele Boaretto and supported by the “Boaretto Group Hotel and Resort”. The name Y-40 is inspired by mathematical symbols. “Y” is the ordinate axis of the Cartesian system and “–40” means the world's record depth or our pool- that is 40 meters underground. (Photo by Courtesy Y40 Deep Joy)

These timeless postcards offer an eye-opening glimpse into life in Japan in the early 20th century. Taken from hand-colored photographs, the postcards showcase the still beauty of the country, depicting a nation on the cusp of modernization. The images feature solemn fishermen, bustling streets, temples and shrines: a country yet to be influenced by Western culture. The tinting effect brings out the rich colors of the natural surroundings, with trees, flowers and cherry blossoms jumping from the original black-and-white images. Here: Toyokuni Shrine Nakanoshima, Osaka, Japan. (Photo by New York Public Library/Caters News)

Divers wearing mermaid costumes take part in the first Chinese Mermaid Performance Contest at Atlantis resort on December 21, 2021 in Sanya, Hainan Province of China. (Photo by Luo Yunfei/China News Service via Getty Images)

A salsa dancer performs in the “Salsodromo” parade, which marks the start of the Fair of Cali, Colombia, December 25, 2015. Picture taken December 25, 2015. (Photo by Jaime Saldarriaga/Reuters)

Battersea Power Station. The chimney rims are thinner on top than you might expect. (Photo by Bradley L. Garrett)

A runner in fancy dress participates in the Virgin London Marathon 2013 on April 21, 2013 in London, England. (Photo by Tom Dulat/Getty Images)

Roped up climbers leave the summit of Breithorn at 4,164 metres (13,661 feet) on the ridge marking the border with Switzerland (left) and Italy in the Alpine resort of Zermatt August 4, 2014. Switzerland will vote on November 30 on an initiative from the group Ecopop which proposes a cap on the number of immigrants. The group says it is motivated by concerns about a lack of living space exerting too much pressure on the land and natural resources, rather than by opposition to foreigners. (Photo by Denis Balibouse/Reuters)

The remarkable scene was captured by amateur wildlife photographer Ian Salisbury, 62, at the South Luangwa National park in Zambia. The crocodile grabs hold of the elephant's trunk, but it soon becomes clear that he has bitten off a lot more than he can chew by grabbing the huge beast. Mr Salisbury said the elephant “fled rapidly into the bush” after the attack. (Photo by Ian Salisbury/Caters News)