Festival goers plays in mud during the 15th Annual Boryeong Mud Festival at Daecheon beach in Boryeong, about 190 km (118 miles) southwest of Seoul, July 15, 2012. About 2 to 3 million domestic and international tourists visit the beach during the annual mud festival, according to the festival organisation. (Photo by Chung Sung-Jun)

A hen, a dog and a rabbit playing cards, circa 1956. (Photo by Evans/Three Lions)

A six-day-old hippopotamus is pictured next to his mother, Kara, aged 21, on September 12, 2012 at “Planet sauvage” (“Wild planet”) Zoo in Port-Saint-Pere, western France. The birth, a rare event for this species in captivity, occured on September 7, 2012 in the Zoo. (Photo by Frank Perry/AFP Photo)

A model presents a creation from Andres Sarda's Fall/Winter 2017 collection during the Mercedes-Benz Fashion Week in Madrid, Spain February 18, 2017. (Photo by Javier Barbancho/Reuters)

Extraordinary images of the cruise ship by Jonathan Danko Kielkowski from his book Concordia, published by White Press. The German photographer swam out to where the ship – which ran aground off Tuscany in 2012 with the loss of 32 lives – is moored. Francesco Schettino, the ship’s captain, was jailed for 16 years over the accident. (Photo by Jonathan Danko Kielkowski)

A police officer lies on the street after being run over by a bus during a protest against the increase in the price of public transport in San Cristobal, Venezuela March 29, 2016. (Photo by Carlos Eduardo Ramirez/Reuters)

Actors portraying "corrupted people" participate in the "Unmask the Corrupt" event, organized by the Transparency International non-governmental organization to create awareness on corruption, in Lima, November 12, 2015. (Photo by Mariana Bazo/Reuters)

Construction continues on One World Trade Center (TALLEST BUILDING AT LOWER LEFT) as the memorial footprints of the twin towers are seen (BOTTOM C) on August 12, 2011 in New York City. Upon completion, One World Trade Center will be New York's tallest skyscraper, topping out at a symbolic 1,776 feet, with 3 million square feet of office space. More than 2,700 people were killed when al-Qaeda terrorists hijacked U.S. passenger jets and flew them into the twin towers of the World Trade Center on September 11, 2001. Nearly ten years after the crippling attacks on Lower Manhattan, business, tourism and new construction like One World Trade Center have rejuvenated the formerly devastated cityscape.(Photo by Mario Tama/Getty Images)