Alain Robert of France, who is known as "Spiderman", climbs the Habana Libre hotel in Havana February 4, 2013. Robert, who scales buildings all over the world without safety equipment, successfully climbed the hotel which is 126 metres (413 feet) high. (Photo by Stringer/Reuters)

A schoolgirl collects rubbish from Karachi's Clifton beach early morning April 22, 2013, during a cleaning campaign as part of the commemoration of Earth Day. (Photo by Akhtar Soomro/Reuters)

Residents of the Korean port of Inchon surrender to American troops. (Photo by Bert Hardy/Getty Images). 1950

An arrow-head discovered in 2006 by Archaeologists of the University of Cambridge Archaeological Unit, is displayed by one of the team uncovering Bronze Age wooden houses, preserved in silt, from a quarry near Peterborough, Britain, January 12, 2016. Archaeologists said on Tuesday they had discovered what were believed to be the best-preserved Bronze Age dwellings ever found in Britain, providing an extraordinary insight into prehistoric life from 3,000 years ago. (Photo by Peter Nicholls/Reuters)

Syrian rescue workers and residents help an injured woman following a reported air strike by government forces on the rebel-held neighbourhood of Haydariya in the northern city of Aleppo on April 10, 2016. (Photo by Thaer Mohammed/AFP Photo)

A box of 36 coloured pencils as photographed in a studio with an illustrative price tag of $115 (US dollars), equivalent to the Bs. 725 (bolivars) that it costs on average to purchase in Caracas at the official exchange rate of 6.3 bolivars per dollar, in Caracas September 29, 2014. Venezuela's economic crisis has led to some shocking and surreal price distortions that hit people's buying power dramatically. (Photo by Carlos Garcia Rawlins/Reuters)

Israeli soldiers of the Search and Rescue brigade take part in a training session in Ben Shemen forest, near the city of Modi'in May 23, 2016. (Photo by Amir Cohen/Reuters)

Chicken, fish and eggs lie next to coca paste worth $14,000 Colombian pesos at a local store in Guyabero Region, Guaviare, Colombia, May 24, 2016. As the government nears a historic peace deal with the rebels of the Revolutionary Armed Forces of Colombia (FARC), the nation's authorities are struggling to tame an increase in farming of coca, the raw material used to make cocaine. In the Guyabero Region, where many people work on coca plantations, locals barter coca paste to buy groceries at the local shop. (Photo by John Vizcaino/Reuters)