A house built on a rock on the river Drina is seen near the western Serbian town of Bajina Basta, about 160km (99 miles) from the capital Belgrade May 22, 2013. The house was built in 1968 by a group of young men who decided that the rock on the river was an ideal place for a tiny shelter, according to the house's co-owner, who was among those involved in its construction. (Photo by Marko Djurica/Reuters)

The sign above the door of restaurant and hotel “Am Paulusbogen” is partially submerged in the flooded centre of the Bavarian town of Passau, about 200 km (124 miles) north-east of Munich June 3, 2013. (Photo by Michaela Rehle/Reuters)

In this Tuesday, June 18, 2013 photo, Zita, a liger – half-lioness, half-tiger – carries her one month-old liliger cub in the Novosibirsk Zoo. The cub's father is a lion, Sam. (Photo by Ilnar Salakhiev/AP Photo)

Patrick Hausding and Stephan Feck of Germany compete in the men's 3-meter synchro springboard preliminary competition at the FINA Swimming World Championships in Barcelona, Spain, Tuesday, July 23, 2013. (Photo by David J. Phillip/AP Photo)

Flames from the Falls Fire burn on a hillside along South Main Divide Road in the Cleveland National Forest as firefighters drive through the area on Monday, August 5, 2013. (Photo by Kurt Miller/AP Photo/The Press-Enterprise)

14 week-old twin polar bear cubs play during their first presentation to the media in Hellabrunn zoo on March 19, 2014 in Munich, Germany. The male and female twins were born on December 9, 2013 in the zoo. (Photo by Alexandra Beier/Getty Images)

Photographer John Maher, once the drummer with punk bank Buzzcocks, travelled to the Outer Hebrides to photograph abandoned crofters’ cottages – many of which, like this one, have seemingly been untouched since. Here: “Peat Fire”. Taken in March 2013 on the east coast of Harris. The fire is from muir-burning, when farmers burn off grasses and heather to improve grazing for their sheep. (Photo by John Maher/The Guardian)

A breeder puts a giant panda cub into a crib at Chengdu Research Base of Giant Panda Breeding in Chengdu, Sichuan province, September 23, 2013. Fourteen new joiners to the 128-giant-panda-family at the base were shown to the public on Monday, according to local media. (Photo by Reuters/China Daily)