People enjoy the view of the Acropolis at Monastiraki square in Athens, Greece, on May 30, 2020. Greece reopened restaurants and cafes on May 25 as Greece is taking steps to restart its tourism sector. (Xinhua/Marios Lolos)

People sit in a restaurant at Monastiraki square in Athens, Greece, on May 30, 2020. Greece reopened restaurants and cafes on May 25 as Greece is taking steps to restart its tourism sector. (Xinhua/Marios Lolos)

People sit in a restaurant at Monastiraki square in Athens, Greece, on May 30, 2020. Greece reopened restaurants and cafes on May 25 as Greece is taking steps to restart its tourism sector. (Xinhua/Marios Lolos)

People walk around Zappeion in Athens, Greece, on May 30, 2020. Greece reopened restaurants and cafes on May 25 as Greece is taking steps to restart its tourism sector. (Xinhua/Marios Lolos)

People rest near Zappeion in Athens, Greece, on May 30, 2020. Greece reopened restaurants and cafes on May 25 as Greece is taking steps to restart its tourism sector. (Xinhua/Marios Lolos)

People walk around Zappeion in Athens, Greece, on May 30, 2020. Greece reopened restaurants and cafes on May 25 as Greece is taking steps to restart its tourism sector. (Xinhua/Marios Lolos)