Fighters of the pro-government Popular Resistance Committees militia carry a cannon as they transport it in parts to Yemen's southwestern war-torn city of Taiz December 26, 2015. (Photo by Reuters/Stringer)

A conductor (C) collects fares from candy floss sellers as they travel in a tram to a marketplace early morning in Kolkata, India, December 23, 2015. (Photo by Rupak De Chowdhuri/Reuters)

A fire engulfs The Address Hotel in downtown Dubai in the United Arab Emirates December 31, 2015. Fire engulfed a luxury building near the world’s tallest skyscraper in Dubai on Thursday as tens of thousands of people were gathering at its base for one of the world’s largest New Year’s fireworks displays. (Photo by Ahmed Jadallah/Reuters)

A colony of penguins gather with the Bark Europa in the background, on March 05, 2015 in South Georgia Island. An adventurer has documented his 5,000 miles journey aboard a 100-year-old ship, sailing from Argentina to Antarctica to Cape Town. (Photo by Andrew Orr/Barcroft Images)

Lioness and hyena posture to one another, in Masai Mara, Kenya, August 2015. A photographer captured one of the oldest rivalries in the animal kingdom as a pair of lions went head to head with a pack of hungry hyenas. (Photo by Ingo Gerlach/Barcroft Images)

A woman takes cover as shots are fired by police officers as they face off with stone-throwing protesters, during an anti-government demonstration in Bujumbura, Burundi, 20 May 2015. Police officers fired shots and teargas canisters in running battles with protesters who demonstrated against Burundi's President Pierre Nkurunziza's bid for a third term. Presidential spokesman man said on 20 May that the country will postpone its parliamentary and local council elections, previously scheduled for 26 May, to 05 June 2015. According to the United Nations' refugee agency, more than 105,000 Burndians have fled the country to seek refuge in neighbouring countries such as Rwanda, DR Congo, and Tanzania. (Photo by Dai Kurokawa/EPA)

Journalists (L) walk along the new Caminito del Rey (The King's Little Pathway) in El Chorro-Alora, near Malaga, southern Spain March 15, 2015. Dubbed by many media outlets as the world's scariest pathway, the three-kilometre long pathway, which was built at about 100 metres (330 ft) above the gorge of Los Gaitanes between the years of 1901 and 1905, was closed in 2001 after five people died. A new walkway has then been built over the old walkway and will open to the public on March 28, 2015. (Photo by Jon Nazca/Reuters)