Tourists take a “selfie” as demonstrators burn a trash container during a May Day rally in Barcelona, Spain, on May 1, 2014. Tens of thousands of workers marked May Day in European cities with a mix of anger and gloom over austerity measures imposed by leaders trying to contain the eurozone's intractable debt crisis. (Photo by Manu Fernandez/Associated Press)

“A fter the former Soviet Union conducted its first nuclear test in August 1949, the US reevaluated its postwar defense policies. With the US monopoly on atomic weapons broken, military and political leaders chose to diversify the American stockpile by developing thermonuclear and tactical nuclear weapons. One of the more interesting concepts to come out of this period was atomic artillery, which was successfully tested at the Nevada Proving Grounds (now the Nevada Test Site) in May 1953”. – Alan Carr. Photo: Atomic Annie at work during the Upshot-Knothole test series, 1953. (Photo by Los Alamos National Laboratory/US Army)

The official name for this tiny speck of land – the size of 12 football pitches – is Hashima, but few call it that. In English, its most commonly used name means “Battleship Island” and, viewed from a certain angle offshore, its silhouette is uncannily dreadnought in nature. It was a mining facility until 1974, when it was abandoned to the elements, before partially reopening as a tourist attraction in 2009. Photo: A decades-old television. (Photo by Mark C. O'Flaherty)

Raising a flag over the Reichstag is a historic World War II photograph taken during the Battle of Berlin on 2 May 1945, by Yevgeny Khaldei.

A rider on horseback competes in the Margalla Festival Tent Pegging Championship in Islamabad, Pakistan, June 5, 2016. Tent pegging is an equestrian sport popular in India and Pakistan, with a history going back to the cavalries of ancient armies. (Photo by Caren Firouz/Reuters)

The report, prepared by the Sustainable Development Solutions Network (SDSN) and the Earth Institute at Columbia University, showed Syria, Afghanistan and eight sub-Saharan countries as the 10 least happy places on earth to live. The top 10 this year were Denmark, Switzerland, Iceland, Norway, Finland, Canada, Netherlands, New Zealand, Australia, and Sweden. Denmark was in third place last year, behind Switzerland and Iceland. The bottom 10 were Madagascar, Tanzania, Liberia, Guinea, Rwanda, Benin, Afghanistan, Togo, Syria and Burundi. The United States came in at 13, the United Kingdom at 23, France at 32, and Italy at 50. Here: #8. NEW ZEALAND: A woman dives from a platform into a giant air bed at a park in Palmerston North September 29, 2011. (Photo by Marcos Brindicci/Reuters)

A demonstrator argues with policewomen after she turned up her shirt and was taken out from a protest to demand the resignation of Brazilian President Dilma Rousseff, on March 13, 2016 in Paulista Avenue in Sao Paulo. Protesters, many draped in the Brazilian national flag, poured into the streets of Brasilia and Rio de Janeiro on Sunday at the start of mass demonstrations seeking to bring down President Dilma Rousseff. Authorities in Sao Paulo, Brazil's biggest city and an opposition stronghold, said they were bracing for a million protesters. (Photo by Miguel Schincariol/AFP Photo)

The symbol for “One Orlando” is spelled out at a makeshift memorial at Lake Eola in downtown Orlando, Fla., Saturday, June 18, 2016. Nearby, visitors lit candles and prayed at a larger memorial, at the Dr. Phillips Center for the Performing Arts, to mourn the victims of the Pulse massacre. (Photo by Joe Burbank/Orlando Sentinel via AP Photo)