Delos
UNESCO World Heritage Site: Delos (1990) Mythical Birthplace Of Apollo And Artemis And A Whole Ancient City On An Uninhabited Island, With The Terrace Of The Lions And The House Of Dionysus · Mykonos, South Aegean
Delos is a small, bare, uninhabited island a short boat ride from Mykonos, and one of the most complete ancient cities in the Mediterranean. In myth it is where Leto gave birth to Apollo and Artemis, and for centuries it was the holiest sanctuary of the Aegean: the treasury of the Athenian-led Delian League sat here, Athens purified the island in 426 BC so that nobody could be born or die on it, and after 166 BC it became a booming free port and slave market where merchants from Italy, Egypt and Syria built houses, shrines and markets. Sacked in the first century BC, it was never rebuilt, so what you walk through is a frozen city: the sanctuary of Apollo, the Terrace of the Lions, the theatre quarter with its mosaic floors, and Mount Kynthos above. It has been a UNESCO World Heritage Site since 1990. The honest caveats: there is almost no shade, no overnight stay is allowed, your day is fixed by the boat timetable, and strong summer wind can cancel the crossing altogether.
Island of Delos, about 2.5 km south-west of Mykonos; boats from the Old Port of Mykonos Town (about 30 minutes), Mykonos, South Aegean, Greece
Seasonal: the site is open roughly from 1 April to 30 November (confirm), with long summer hours and shorter ones in spring and autumn; in some years it has closed one weekday, historically Monday, so confirm the day. It shuts on the national holidays when state sites close. In practice the boat, not the gate, sets your hours: boats leave the Old Port of Mykonos Town (about 30 minutes) with several morning departures and return in the afternoon, and the last boat back ends your day - nobody may stay the night. Buy the boat ticket at the port kiosks or ahead in July and August; the site ticket is sold at the landing or on the official Hellenic Heritage e-ticket system. Boats do not run in strong wind.