The ancient city of Thera is located on Mesa Vouno, 396 m. above sea level. It was founded in the 9th century BC by Dorian colonists whose leader was Theras, and continued to be inhabited until the Early Byzantine period.
The preserved ruins belong mainly to the Hellenistic and Roman phases of the city. The residential area and the larger part of the cemeteries were excavated by German archaeologists between 1895 and 1902. The cemeteries on the NE and NW slopes of Sellada were excavated by N. Zapheiropoulos in the years 1961-1982.
The most important monuments of the site are: The Sanctuary of Artemidoros, entirely hewn in the rock, was founded by Artemidoros of
The surface of the rock was engraved with epigrams, inscriptions and the symbols of the gods worshipped: an eagle for Zeus, a lion for Apollo, a dolphin for Poseidon. Also engraved is the portrait of the wreathed Artemidoros, the founder of the sanctuary. The whole structure is dated to the end of the 4th or the beginning of the 3rd century BC. The Agora occupies the centre of the city. Its southern part was actually the commercial centre and the middle one was the administrative centre. The northern part was
added in the Roman period and included a portico, monuments and temple-like buildings, erected in honor of distinguished persons. The Royal Stoa(46 x 10 m.) was built in the time of Augustus (1st century AD),
in the SW part of the Agora. The main entrance is on the east side, towards the Agora and the roof was supported by an interior Doric colonnade along the axis of the building. Statues of members of the Ceasar's family were erected in the north part. Two inscribed slabs built in the west wall, record that the portico was repaired in AD 149 by Kleitosthenes, a rich Theran. The temple of Dionysos is a small, Doric temple with a small cella and pronaos,
built on an artificial terrace to the north of the Agora. The facade and roof were made of marble while the rest of the building was of local stone. Dated to the 3rd century BC. The area of the sanctuaries. The SE area is occupied exclusively by sanctuaries,
open-air or roofed (such as the sanctuary of Apollo Karneios, of Hermes and Heracles, of Ptolemy III) and the square, where the Gymnopaediae (dances of nude boys) were held in honor of Apollo Karneios. Engraved on the rocks are numerous inscriptions dating from the Archaic to the Roman period, referring to deities and youths. The sanctuary of Apollo Karneios, dated to the 6th century BC, is partially hewn from the rock and partially built on an artificial terrace. It includes the temple with pronaos and cella, a square courtyard with an underground cistern, the roof of which was supported by six large monolithic pillars and a small building, probably a repository. The Gymnasium lies at the south edge of the city and dates from the 2nd century
AD. A small cave, partially hewn from the rock, was dedicated to Hermes and Heracles. The cemeteries of ancient Thera are located on the slopes of the Sellada, on either
side of the roads that led to the north and south harbours of the ancient city, where the modern villages of
and Perissa are.
The graves uncovered span from the Geometric to the Roman times. The theatre lies to the SE of the Agora. It was constructed in the Ptolemaic period
(3rd century BC) and in its original form had a circular orchestra. During alterations in the 1st century AD, the stage was extended and took over part of the original orchestra.