A pro-democracy demonstrator fights with a Soviet soldier on top of a tank parked in front of the Russian Federation building on August 19, 1991, after a coup toppled Soviet President Mikhail Gorbachev. The same day, thousands in Moscow, Leningrad, and other cities answered Russian Republic President Boris Yeltsin's call to raise barricades against tanks and troops. (Dima Tanin/AFP/Getty Images)

“Only the most intrepid urban explorers cross the tattered ruins of the old Iron Curtain to endure the excessive bureaucracy, military paranoia and freezing winds of the East to hunt for the ghosts of an empire. Rebecca Litchfield is one who couldn't resist the haunting allure of the ruins of the Soviet Union”. – Yahoo News. Photo: Hungary, MAV 424 Steam Train. (Photo by Rebecca Bathory)

The Mexico – United States barrier – also known in the United States as the border fence, rotted fence or border wall – is actually several separation barriers designed to prevent illegal movement across the Mexico – United States border.

A Kurdish female fighter from the People's Protection Units (YPG) gestures as she carries her weapon near al-Hawl area where fighting between Islamic State fighters and fighters from Democratic Forces of Syria are taking place in south-eastern city of Hasaka, Syria November 10, 2015. (Photo by Rodi Said/Reuters)

The barren landscapes of the south-western US provided inspiration for photographer David Clapp. He visited Nevada, New Mexico, Utah and Arizona as part of his project on other-worldy locations, with surreal results. Here: An infrared image at dusk of strange clay rock formations in Ah-Shi-Sle-Pah Wilderness in Farmington, New Mexico. (Photo by David Clapp/Barcroft Images)

Men work at a makeshift oil refinery site in Marchmarin town, southern countryside of Idlib, Syria December 16, 2015. The refinery site, owned by Yousef Ayoub, 34, has been active for 4 months. Ayoub says that he gets the crude oil from Islamic State-controlled areas in Deir al-Zor province and Iraq. The price for a barrel of crude oil varies and is controlled by the Islamic State, but it is currently at $44 dollars per barrel, he said. (Photo by Khalil Ashawi/Reuters)

It’s the United States of Air-merica! Pilot Jassen Todorov from San Francisco spent three weeks flying across eight states in a 1976 Piper Warrior plane to capture the this shots – from deep craters in Arizona’s red desert and the swamps and wetlands in Florida and Louisiana, that look like they could be on alien planets, to freeways and stretches of suburban Texas. Here: El Paso, Texas at sunset. (Photo by Jassen Todorov/Caters News)

Gianluca Pardelli is something of an expert on markets. For the past two years, he’s travelled across eastern Europe, from Azerbaijan to Uzbekistan, Moldova to Georgia, photographing them. Here: Telavi, Georgia. (Photo by Gianluca Pardelli)