A Kurdish girl wears her relative's assault rifle and ammunition belt as she waits at the Iraqi Kurdish Shaqouli checkpoint, some 35 kilometres east of Mosul, on November 10, 2016. Since the start of the Mosul offensive the Kurds have moved their border some 10 kms closer to Iraq's second city, marking it out with a line in the sand. (Photo by Odd Andersen/AFP Photo)

A man suffering from mental illness sits chained on a bed in his room inside his family home in Curug Sulanjana village in Serang, Banten province, Indonesia March 23, 2016. In a programme launched this year, Indonesia sends teams of workers into often-remote hamlets to help free patients kept in chains and ensure they get the medical treatment they need. (Photo by Reuters/Beawiharta)

Animal rights activists from the group “Animal Equality” are covered with plastic sheets to represent meat packaging as they stage a protest during “Day Without Meat” event in Barcelona, Spain, on March 20, 2013. (Photo by Lluis Gene/AFP Photo)

Uranjargal, a leader of the Mongolian neo-Nazi group Tsagaan Khass, stands next to a statue of Chingunjav, a Mongolian national hero, in Ulan Bator June 22, 2013. The group has rebranded itself as an environmentalist organisation fighting pollution by foreign-owned mines, seeking legitimacy as it sends Swastika-wearing members to check mining permits. Over the past years, ultra-nationalist groups have expanded in the country and among those garnering attention is Tsagaan Khass, which has recently shifted its focus from activities such as attacks on women it accuses of consorting with foreign men to environmental issues, with the stated goal of protecting Mongolia from foreign mining interests. This ultra-nationalist group was founded in the 1990s and currently has 100-plus members. (Photo by Carlos Barria/Reuters)

The Brooklyn Bridge is seen after a crane pulled by a tug boat on the East River slammed into scaffolding beneath the Bridge on March 13, 2012 in New York, NY. According to reports, no damage was done to the structure of the bridge. (Photo by Allison Joyce/Getty Images)

These are the ambitious plans which suggest skyscrapers of the future may house an entire city. The Endless City project is an award-winning proposal by sure Architecture, who propose turning skyscrapers into complete ecosystems. London is the proposed city for the mixed-use tower – which would feature huge ramps linking different sections of the structure. The company, whose design won the SkyScrapers and SuperSkyScrapers Competition, insist the structure would be a great space-saver in dense cities which have previously spread outwards rather than upwards. (Photo by Caters News)

Star trails are pictured from a road in Singapore. These astonishing images of night sky are captured by Singapore based photographer Justin Ng. The pictures were taken between November 2013 to January 2014. It show's star trail caused by the earth's rotation and also can be achieved by zooming the DSLR lens inward or outward in small steps using a dedicated motorized zooming device. (Photo by Justin Ng/Barcroft Media)

Drivers push cars to gas station during “oil crisis”, Roslindale, Boston, Massachusetts, 1973. (Photo by Spencer Grant/Getty Images)