Boys play football in a shantytown of Olinda, about 18 km from Recife in northeastern Brazil, on June 18, 2013 as the FIFA Confederations Cup Brazil 2013 football tournament is being held in the country. The historic centre of Olinda is listed as an UNESCO World Heritage Site. (Photo by Yasuyoshi Chiba/AFP Photo)

Replica of an old traditional Icelandic house from the 1800 with eruption of Iceland's Eyjafjallajökull volcano, 2013. (Photo by Ingólfur Bjargmundsson/Getty Images)

Four men dressed as zombies participate in a Zombie Walk procession in the streets of Paris October 12, 2013. (Photo by Benoit Tessier/Reuters)

A young Free Syrian Army fighter holds a rifle in Haresta neighbourhood of Damascus January 16, 2013. (Photo by Goran Tomasevic/Reuters)

An enthusiast dressed as a zombie takes part in the annual Zombie Walk festival in Prague June 1, 2013. (Photo by David W. Cerny/Reuters)

“In beard and hat”; Udine, Friuli-Venezia Giulia, Italy, 2013. (Photo by Giulio Magnifico)

Huge pack of starlings in the sky of the Negev, Israel, on January 21, 2013. Birds are turned in evening twilight before settling to sleep. (Photo by Eliyahu Hershkovitz)

A burning tank is in Daraa, on March 9, 2013. (Photo by Ali Abu-Salah/Reuters/Shaam News Network via The Atlantic)