The position of the ancient deme of Thorikos was located on the hill Velatouri on the edge of the plain of modern Thorikos, near the sea.
Among the oldest ancient demes of Attica, Thorikos was one of the 12 settlements (komai) that, according to tradition, took part in the political unification under Athens (synoikismos) by Theseus.
Due to its proximity to the mines of Lavrion, Thorikos was the mining centre of Lavreotika region. The site was inhabited from the Neolithic age (ca. 4500 BC) and without interruption until the 1st century BC.
The excavations have brought to light part of the prehistoric settlement, as well as an extensive part of the historical deme, namely residential quarters, cemeteries, the theater, and the so-called "industrial quarter", along with ancient mines. It is noteworthy that mine extraction in Thorikos dates back to around 3000 BC. After the exhaustion of the mines of Lavrion and the destruction of Thorikos by the Roman general Sulla in 86 BC the area was abandoned temporarily. It was reinhabited during the Roman period until the 6th century AD, when the countryside of Attica was deserted due to the Slavic invasions .
The archaeological research in the area was initiated by the Society of Dilettanti in the early 19th century. In 1886 the American School of Classical Studies conducted here its first excavation in Greece, followed in 1893-94 by the Archaeological Society of Athens. But with Thorikos has mainly associated its history the Belgian School at Athens. In 1963 commenced the archaeological exploration on the site which would last for decades, focused on the fortified acropolis, the theatre, the mines and ore plants of the 5th and 4th centuries BC.
Early and Middle Helladic Houses (2900-1600) from the Bronze Age settlement that expanded on the top of the hill.
The monumental tholos (vaulted) and chamber tombs of the Mycenaean period (1600-1100),
which yielded important evidence related with the mine extraction activities in that period.
The theatre. Unique due to its shape which comprises
an elongated layout with an oval orchestra, it was built in the late 6th century BC and it is
the earliest found so far in Greece. The theatre was excavated by the American School of Classical Studies in 1886.
The "Industrial Quarter". The nucleus of the ancient settlement of Thorikos lay on the west slope of the Velatouri hill.
The excavations revealed the picture of a densely populated and flourishing city of the 5th and 4th centuries BC, with private houses, stoae, workshops and ore plants, e.g.
The "Temple of Demeter and Kore (Daughter)" is a large marble building in the shape of a double stoa and of Doric order. It is dated to the 5th century BC and its identification was based
on an inscription found in situ. The monument was excavated by the Society of Dilettanti in 1817.