In this Saturday, June 14, 2014 file photo, two women kiss in front of a rainbow flag, the symbol of the gay rights movement, during the Gay Pride parade in central Athens, Greece. Ahead of May 21, general elections, Alexis Tsipras, head of the main left-wing opposition party, Syriza, promised on Tuesday, April 4, 2023 to legalize same-s*x marriage if he becomes the next prime minister. (Photo by Petros Giannakouris/AP Photo)

A boy and a serviceman pose for a picture during Marines Day celebration in the Black Sea port of Sevastopol, Crimea, November 27, 2016. (Photo by Pavel Rebrov/Reuters)

A demonstrator is carried during a rally in support of a identity check draft law and against delinquency, in Santiago, Chile April 30, 2016. (Photo by Carlos Vera/Reuters)

A photograph made available on 30 September 2016 showing wind turbines at the site of the highest wind park in Europe at the Griessee, near the Nufenenpass in the Swiss south Alpes, Valais, Switzerland, on 23 September 2016. The four wind turbines of this wind park were developed by the company SwissWinds GmbH and are inaugurated on, 30 September 2016. (Photo by Olivier Maire/EPA)

Couples take part in a competition during a mass wedding of 64 doctoral student couples at Harbin Institute of Technology, a university in Harbin, Heilongjiang province, China, June 4, 2017. (Photo by Reuters/Stringer)

A man flies a kite on the Bund while buildings of Pudong's Lujiazui financial district stand across the Huangpu River as the sun rises in Shanghai, China, on Friday, October 2, 2015. (Photo by Qilai Shen/Bloomberg)

These stunning pictures of beautiful Icelandic waterfalls will take your breath away. The mesmerizing shots show the striking waterfalls set against the night sky and the hypnotic green glow of the northern lights, as well as the picturesque Icelandic scenery and stunning sunrises. Here: A mesmerising waterfall in the Icelandic country-side. (Photo by Arnar Kristjansson/Caters News)

Gunfire was brought to the steps of President Truman's Washington home, Blair House, as two assassins tried to kill the chief executive, November 1, 1950. One of the gunmen, Oscar Collazzo of New York, lay wounded at the bottom of Blair House's front steps after the president's police guard had finished their work, at the cost of one guards' life, Dec. 9, 1950. The second gunman was killed. (Photo by Harvey Georges/AP Photo)