Residents of the Brussels suburb of Molenbeek are searched by police before taking part in a memorial gathering to honour the victims of the recent deadly Paris attacks, in Brussels, Belgium, November 18, 2015. (Photo by Yves Herman/Reuters)

In this photograph taken on June 28, 2015, a hiker in Hong Kong takes a picture of the city from a walking trail. The southern Chinese territory is crisscrossed by more than 180 miles of designated hiking trails. (Photo by Alex Ogle/AFP Photo)

A Russian prisoner eating bread. (Photo by Hulton Archive/Getty Images). Finland, circa 1940

People walk past debris on May 3, 2015 in Bhaktapur, Nepal. A major 7.8 earthquake hit Kathmandu mid-day on Saturday, and was followed by multiple aftershocks that triggered avalanches on Mt. Everest that buried mountain climbers in their base camps. (Photo by David Ramos/Getty Images)

Voters line up to cast their ballots at a polling station in the city of Qom, Iran. Elections for Iran's parliament (Majlis) and Assembly of Experts kicked off on Friday, February 26, 2016. (Photo by Ahmad Halabisaz/Xinhua via ZUMA Wire)

A member of the “Castellers Minyons de Terrassa” adjusts her belt before forming a human tower or ÒcastellÓ during the festival of the patron saint of Barcelona “The Virgin of Mercy” at Sant Jaume square in Barcelona, Spain, September 20, 2015. The formation of human towers is a tradition in Catalonia dating back to the 18th century. (Photo by Susana Vera/Reuters)

Chinelos (traditional costumed dancers) perform in front of San Andres Ocotlan church as part of continuing festivities to welcome the new year in Calimaya, Mexico on January 4, 2016. (Photo by Arturo Hernandez/Demotix/Corbis)

Iraq's second largest city, Mosul, is locked under the rule of extremists from the Islamic State group trying to purge it of everything they see as contradicting their stark vision of Islam. A trove of photographs now housed at the Library of Congress offers a glimpse of a different Mosul – before wars, insurgency, sectarian strife and now radicals' rule. The scenes were taken in the autumn of 1932 by staff from the American Colony Photo Department during a visit to Iraq at the end of the British mandate. (Photo by AP Photo)