A rainbow appears over the Louisiana gulf May 26, 2010 in the Gulf of Mexico near Brush Island, Louisiana. (Photo by Win McNamee/Getty Images)

An employee walks past a rotary dredge working at an open-cast iron ore mine of the Stoilensky mining and concentration plant (GOK), owned by the Novolipetsk (NLMK) steel mill, in the city of Stary Oskol in Belgorod region, Russia, August 4, 2015. (Photo by Maxim Shemetov/Reuters)

Aerial photography platform SkyPixel received 27,000 entries to its 2016 competition. Here are the winning shots plus some of our favourites. Here: Dam near perfect. Second prize in the same category was of the Huia Dam in Auckland, New Zealand. Hong Kong-based SkyPixel was launched in 2014. (Photo by Brendon Dixon/SkyPixel)

People walk on a sightseeing platform in Zhangjiajie, Hunan Province, China, August 1, 2016. China has opened a 100-metre-long glass skywalk stretching around a cliff on the side of the Tianmen Mountain. The skywalk provides a view of a 300-metre drop and overlooks Tongtian Avenue, a mountain road with 99 turns that snakes up the mountain. When translated in English, it means “Avenue to the Sky”. (Photo by Reuters/Stringer)

Swimmers in fancy costume take part in the New Year's Day swim at Saundersfoot in Wales, Britain, January 1, 2017. (Photo by Rebecca Naden/Reuters)

A man poses for a picture to show his rings of gold, silver and bronze on his fist in Zamfara, Nigeria April 21, 2016. (Photo by Afolabi Sotunde/Reuters)

Irwan bathes a domesticated crocodile at his house in Bogor, Indonesia on January 22, 2018. Irwan found it as a baby and now it has been living with Irwans family for 20 years. Indonesia is known as a hotbed of exotic pet domestication and trade. People have been known to keep endangered animals such as slow lorises, eagles and pangolins, angering conservationists and animal rights activists. (Photo by Eko Siswono Toyudho/Anadolu Agency/Getty Images)

Actors dressed as Santa Claus take a refreshing bath at Bellevue Beach north of Copenhagen, Denmark, on July 24, 2018, as they take part in the World Santa Congress, an annual two-day event held every summer in Copenhagen. (Photo by Mads Claus Rasmussen/AFP Photo/Ritzau Scanpix)