Syrian government troops patrol the newly captured al- Sakhour neighbourhood in the eastern part of the northern city of Aleppo on December 7, 2016 Rebels in Aleppo called for a five- day truce and the evacuation of civilians Wednesday after losing more than three quarters of their territory including the Old City to a Syrian army offensive. (Photo by George Ourfalian/AFP Photo)

Festival goers having fun at the Balaton Sound music festival in Zamardi next to the Lake of Balaton, 110 km (68 miles) west of Budapest, July 8, 2017. (Photo by Sandor Csudai)

A general view of the sunrise over Hawes, Wensleydale, UK on November 24, 2014. (Photo by Neil Squires/PA Wire)

Recycling artist Nicolas Gomez checks the strings of a cello he has made out of an oil barrel for the Orchestra of Recycled Instruments of Cateura, in Cateura, Paraguay February 13, 2015. Saudi Arabia's oil exports have risen in February in response to stronger demand from customers. As OPEC's top producer battles for market share Reuters photographers around the globe have been photographing oil barrels to document how they are utilised once the fuel has been used. (Photo by Jorge Adorno/Reuters)

Israeli soldiers detain a protester during a demonstration by Palestinians protesting against the Israeli-built West Bank separation barrier and calling for the right of return for Palestinian refugees, in the northern West Bank city of Tulkarem, on May 31, 2014. (AP Photo/Nasser Ishtayeh)

These frozen caves seem almost otherworldly as they daylight illuminates them. Matej Kriz’s shots reveal the beauty of the brilliant caves, but he’s also very aware of how deadly they can be. The photographer captured the amazing shots in the Vatnajokull National Park on the Breidamerkurjokull glacier tongue. Here: The ice caves, taken in the Vatnajokull National Park in Iceland, on November 11, 2017. (Photo by Matej Kriz/Caters News Agency)

Underwater photographer of the year – winner. Dancing Octopus by Gabriel Barathieu (France). Location: Island of Mayotte, off the coast of south-east Africa. “Balletic and malevolent”, one judge said of this octopus, hunting in a lagoon. Barathieu waited until spring tides when there was just 30cm of water on the flats and plenty of light in the shallows. (Photo by Gabriel Barathieu/UPY2017)