Delos (Little Delos) was, according to mythical tradition, the birthplace of Apollo and Artemis, one of the most important sanctuaries in the Greek world, and the largest religious and political center of the Ionians.

According to mythology, Leto fled here, pursued by the jealous Hera, to bring to light the son of Zeus, the most beautiful of the immortals. The ancient Greeks believed that the hitherto ‘adelos’ (invisible) Asteria, as the island was called before, floated on the sea.

With the birth of the god, the ‘adelos’ became Delos, meaning visible, and was flooded with light and flowers, and according to legend, was tied to the seabed with adamantine chains.

The sanctuary of Apollo is accessible from the port (ancient port facilities and a series of shops), from the South via a sacred road between the stoa of Philip V of Macedonia and the southern stoa, while from the North it is bordered by the long stoa of the Macedonian king Antigonos Gonatas with the Minoan fountain behind it. The center of worship is located in the area of the three temples of Apollo oriented towards the West where the large unique altar covered with an arch, the Keraton, which according to tradition Apollo himself built from goat horns.

Separate are the sanctuaries of Artemis in the South and in the North of Leto and the Twelve Gods. In the area of Apollo’s sanctuary, there are primordial cult remains (the Mycenaean-era tomb-case and the ‘sign’ of the Hyperborean Maidens) and outside the sanctuary, the Archegesion.

Inside the sanctuary, the monument of the bulls, a Hellenistic dedication in the form of a ship for some royal naval victory, the so-called ‘treasuries’ (perhaps houses for cultic meals) and the prytaneion. Agoras of the Italians, the Competaliasts or Hermaists (slaves and freedmen), of Theophrastus and the Delians (commercial and political agora) and various public buildings around Apollo’s sanctuary.

Further away, the sanctuaries of Aphrodite and Hera (7th – 6th century BC), sanctuaries of indigenous deities and a cult cave on Mount Kynthos. To the NE and North, gymnasium, palaestras, stadium, hippodrome.

Around Apollo’s sanctuary, the unwalled city develops, evolving into a cosmopolitan center in the last pre-Christian centuries. In this evolved form, the city surrounds the sanctuary in an arc, in islands with centers of topographical or urban poles (theater, Inopos river) and with open spaces.

It is the best-preserved ancient city in Greece.

In the 7th century BC, the presence of the Naxians is evident on the island (house of the Naxians, lions between the sacred lake – birthplace of Apollo and his sister Artemis – and the Letoon, colossal statue of Apollo, of which parts and its base survive).

From the time of Peisistratus (540-528 BC), Athenian dominance on the island becomes evident, (poros Ionic temple of Apollo). After the Persian Wars, from 478 BC, it is the seat of the First Athenian League. Between 314 BC and 167 BC, Delos is independent and participates in the ‘League of Islanders’ under Ptolemaic leadership. The construction of the large Doric peripteral temple of Apollo continues.

In 167 BC, by decision of the Roman Senate, it is declared a free port and passes under Athenian control. In 88 BC, it is plundered by Mithridates and in 69 BC by the pirates of Athenodorus. In the 2^nd and 1^st centuries BC, the establishment of foreign cults next to the indigenous ones is noted (three sanctuaries of Sarapis and Egyptian deities, sanctuary of Syrian deities, religious association of Poseidoniasts of Berytus and an Israelite synagogue, the oldest of the diaspora). Luxurious houses from these times, with peristyles, often two-storied, with wall paintings and famous mosaic floors are preserved in the theater district (the theater was built around 250 BC).

In the 4^th century AD, Delos is promoted to a bishopric. In the 7^th century AD, the island is abandoned. Southeast of the Delian agora, a single-aisled basilica from the mid-6th century dedicated to Saint Kerykos was excavated. A second single-aisled basilica (perhaps 7^th century AD) near the Asklepieion.

In the local Museum, there is a multitude of sculptures and mosaic floors that attest to the artistic flourishing in the Hellenistic era.