Downhill bikers Kemal Mulic (R-L), Tarik Hadzic and Kamer Kolar train on the disused bobsled track from the 1984 Sarajevo Winter Olympics on Trebevic mountain near Sarajevo, Bosnia and Herzegovina, August 8, 2015. Abandoned and left to crumble into oblivion, most of the 1984 Winter Olympic venues in Bosnia's capital Sarajevo have been reduced to rubble by neglect as much as the 1990s conflict that tore apart the former Yugoslavia. (Photo by Dado Ruvic/Reuters)

An African migrant stranded in Costa Rica bathes at a makeshift camp at the border between Costa Rica and Nicaragua, in Penas Blancas, Costa Rica, July 14, 2016. Thousands of African migrants are currently stranded in Costa Rica after they were denied entry into neighbouring Nicaragua, which they have been using as a crossing point in order to reach the United States. According to the Costa Rican Red Cross, most of these people from Africa, Asia and Haiti. It has been reported that many of them paid smugglers to reach Central America. However, when they arrived at the border gates, they were denied entry and were left with nowhere to go. (Photo by Juan Carlos Ulate/Reuters)

A period of relative stability has put the Iranian capital No1 on the list of world cities that have achieved biggest improvements in liveability over the past five years, as calculated by the Economist Intelligence Unit. The “most improved” top 10 contains some unexpected names. So, eg, the fourth place: Abidjan, Ivory Coast. Latest ranking: 128; Ranking five years ago: 131; Five-year index movement: 3.8%. Here: A supporter of Ivory Coast president Alassane Ouattara campaigns in a market in the city’s Koumassi quarter. (Photo by Sia Kambou/AFP Photo)

The ferocity of crises worldwide is forcing a record number of people to flee their homes, seeking some form of safety within their own country or across international borders. There are 65.3 million displaced people worldwide, including 21.3 million refugees. Most have lost their homes to armed conflict or natural disasters but other factors, such as extreme poverty and climate change, also drive displacement. The International Organisation for Migration commissioned photojournalist Muse Mohammed to document the plight of the displaced. (Photo by Muse Mohammed/IOM)

Handler Jorge Garcia-Bengochea holds Honor, a miniature therapy horse from Gentle Carousel Miniature Therapy Horses, as they visit with patients at the Kravis Children's Hospital at Mount Sinai in the Manhattan borough of New York City, March 16, 2016. Some of the most powerful medicine delivered to young patients at Mount Sinai Hospital in New York on Wednesday came in a package less than 32 inches tall and with a tail. Honor, a 10-month-old colt with Gentle Carousel Miniature Therapy Horses, trotted into the hearts of dozens of children and teens being treated at the Manhattan hospital. (Photo by Mike Segar/Reuters)

Children fill plastic containers with water from a well on a street, close to a neighbourhood called “The Tank” in the slum of Petare in Caracas, Venezuela, March 17, 2016. Although their nation has one of the world's biggest hydroelectric dams and vast rivers like the fabled Orinoco, Venezuelans are still suffering water and power cuts most days. The problems with stuttering services have escalated in the last few weeks: yet another headache for the OPEC nation's 30 million people already reeling from recession, the world's highest inflation rate, and scarcities of basic goods. President Nicolas Maduro blames a drought, while the opposition blames government incompetence. (Photo by Carlos Garcia Rawlins/Reuters)

Rolando Pujol Rodriguez photographed the Cuban raft exodus in 1994, and twenty years later Enrique de la Osa took portraits of some of the people who made it to the United States, in this story which combines archive and present day images. Here: People put the finishing touches to a makeshift boat on a rooftop before lowering it onto a truck and launching it into the Straits of Florida towards the U.S., on the last day of the 1994 Cuban raft exodus in Havana, in this September 13, 1994 file photo. (Photo by Rolando Pujol Rodriguez/Reuters)

Participants take pictures of themselves as others run past the Tiananmen gate during the Beijing Marathon in Beijing, China, September 17, 2016. (Photo by Damir Sagolj/Reuters)