Ngorongoro Crater (Tanzania). At 610m deep and 260 sq km, this is the largest unflooded caldera in the world. A blue-green vision from above it's a haven for engangered wildlife and Maasai livestock. The crater was formed three million years ago when a giant volcano, which could have been as high as Kilimanjaro, exploded and collapsed. The caldera formed the concentric fractures in the crust cracked down to a magma reservoir deep underground. (Photo by John Bryant/Getty Images)

Unforgiving temperatures of up to 60℃ (140℉) beat down on these saltminers on a daily basis. The mines, situated in the Afar Triangle in Ethiopia, stretch across 38,000 sq miles and at their lowest point are more than 300ft below sea level. Joel Santos travelled to capture the area’s dry, brutal beauty. Here: Dromedaries and donkeys are used to transport the salt. (Photo by Joel Santos/Barcroft Images)

Cemetery overcrowding is an issue that resonates around the world, particularly in its most cramped cities and among religions that forbid or discourage cremation. The reality of relying on finite land resources to cope with the endless stream of the dying has brought about creative solutions... (Photo by Rodrigo Abd/AP Photo)

For most ironing is one of those boring chores we tend to put off doing – but for one teenager ironing has become something of an extreme sport. Kevin Krupitzer, 17, has turned the mundane into the insane by taking his ironing board to the most extraordinary of locations, from the edge of cliff to on board a canoe. The daring teenager travels around his hometown of Gilbert, Arizona in search of the weirdest places to iron. And he has even climbed to the top of a 120ft high rock, dubbed the Totem Pole in Queen Creek Canyon, AZ in pursuit of his bizarre hobby. (Photo by Kevin Krupitzer/Caters News)

This picture taken on May 23, 2017 shows visitors posing for photos along a path at an Indonesian hamlet dubbed “the rainbow village” in Semarang, central Java, that has become an internet sensation and attracting hordes of visitors. (Photo by Suryo Wibowo/AFP Photo)

A restaurant in Chelsea is giving customers the ultimate post-pub treat – by selling a burger for £1,100. The world's most expensive burger, dubbed the “Glamburger”, is stuffed with a burger patty made from 220 grams of Kobe Wagyu beef minced with 60 grams of New Zealand venison and seasoned with smoked Himalayan salt. (Photo by Groupon)

Children's author and charity fundraiser Chris Green, of Embsay, near Skipton, has been dubbed “Rhino Boy” as he has pledged to run 40 marathons and other events dressed as a Rhino to raise money for Save the Rhino on January 2020. (Photo by South West News Service/Yorkshire Post)