In pics: changing of the Presidential Guard ceremony in Athens, Greece

People watch members of the Presidential Guard during the changing of the guard ceremony in front of the parliament building in Athens, Greece, on May 20, 2018. The Presidential Guard, also called the Evzones, is a special unit of the Hellenic Army, whose members stand proudly in perfect stillness in front of the Parliament building, guarding the Monument of the Unknown Soldier. (Xinhua/Marios Lolos)