A tourist take a photograph of a sulphur lake in the Danakil Depression on January 23, 2017 near Dallol, Ethiopia. The depression lies 100 metres below sea level and is one of the hottest and most inhospitable places on Earth. Despite the gruelling conditions, Ethiopians continue a centuries old industry of mining salt from the ground by hand in temperatures that average 34.5 degrees centigrade but have risen to over 50 degrees. (Photo by Carl Court/Getty Images)

A Hindu holy man, or sadhu, sits beside a fire after smearing his body with ashes at the premises of Pashupatinath Temple, ahead of the Shivaratri festival in Kathmandu, Nepal February 21, 2017. Hindus mark the Maha Shivratri festival by offering special prayers and fasting, with sadhus arriving at Pashupatinath to take part in the event, which takes place on February 24. (Photo by Navesh Chitrakar/Reuters)

Employee Victoria Livesey walks past Banksy's “Kate Moss 2005” on display at Bonhams on March 23, 2012 in London, England. The painting, estimated at GBP 30,000 – 50,000, USD 48,000 – 79,000 and 35,000 – 59,000 euros forms part of the Urban Art Sale, which takes place at Bonhams on March 29, 2012. (Photo by Peter Macdiarmid/Getty Images)

Mike De Butts adds the finishing touches to a giant Baobab Tree sculpture entitled “Under the Baobab”, outside the Southbank Centre on May 24, 2012 in London, England. The Pirate Technics' installation is made from a selection of brightly coloured fabrics from around the world, and is part of the Southbank Centre's “Festival of the World” exhibition, which includes a series of large scale pieces of art that will be in place around the Southbank centre over the Summer. (Photo by Dan Kitwood)