Men rest after salvaging metal on the 30th floor of the “Tower of David” skyscraper in Caracas February 3, 2014. A 45-storey skyscraper in the center of Venezuela's capital Caracas is a slum, probably the highest in the world. Dubbed the “Tower of David”, the building was intended to be a shining new financial center but was abandoned around 1994 after the death of its developer – banker and horse-breeder David Brillembourg – and the collapse of the financial sector. (Photo by Jorge Silva/Reuters)

Men try to get control of a bucking horse a Tradition Day rodeo exhibition during, in San Antonio de Areco, Argentina, Sunday, November 13, 2022. Tradition Day, aimed to preserve gaucho traditions, is celebrated to honor the birth of Argentine writer Jose Hernandez, author of the country's national poem, “The Gaucho Martin Fierro”. (Photo by Natacha Pisarenko/AP Photo)

Members of the media film as a ranger performs a post mortem on the carcass of a rhino after it was killed for its horn by poachers at the Kruger national park in Mpumalanga province August 27, 2014. Rhino poachers in South Africa now risk giving themselves away when they shoot thanks to a high-tech, gunfire-detection system being piloted in the country's flagship Kruger National Park. The stakes are high, for rhinos are being slain in escalating numbers for their prized horns, alarming both conservationists and the government since wildlife in South Africa is an important tourist draw. (Photo by Siphiwe Sibeko/Reuters)

Men dressed as Vikings lead the torchlight procession as it makes its way along Princess Street for the start of the New Year celebrations December 30, 2011 in Edinburgh, Scotland. Thousands of people joined in the torchlight procession, which is followed by the burning of a Viking long ship, to mark the start of Edinburgh's Hogmanay celebrations. (Photo by Jeff J. Mitchell/Getty Images)

A man dressed as a zombie poses during the Thrill The World 2009 event, which sees fans from all over the world dance simultaneous to Michael Jackson's “Thriller” at Luna Park on October 25, 2009 in Sydney, Australia. (Photo by Brendon Thorne/Getty Images)

Revellers take part in the annual “Naval Battle” of Vallecas in Madrid, Spain July 19, 2015. The slogan for this year's water battle is “Get wet for Alfon, freedom for Alfon”, referring to Alfonso Fernandez Ortega, a Vallecas resident who was sentenced to four years in prison in June. The festival was started spontaneously in 1981 when some neighbours started to throw water at one another due to high temperatures during the Virgen del Carmen Festival. (Photo by Juan Medina/Reuters)

A Dutch Military Policeman, left inside, guards part of the reconstructed cockpit, right, and forward section of the fuselage after the Dutch Safety Board presented it's final report into what caused Malaysia Airlines Flight 17 to break up high over Eastern Ukraine last year, killing all 298 people on board, during a press conference in Gilze-Rijen, central Netherlands, Tuesday, October 13, 2015. (Photo by Peter Dejong/AP Photo)

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)