Ruin of the classical fortification on Külahlıkırtepe (Kadıoğlu, 2021, 153, Figure 54)
Ancient sources mention a defensive wall at Teos dating to the last quarter of the 5th century BC and the middle of the 4th century BC. In the twentieth year of the Peloponnesian War (in the summer of 412 BC), the Spartans and Athenians fought fiercely over the prosperous city of Teos. Archaeological research offers sufficient clues about the location of the wall built by the Athenians outside the city and mentioned by Thucydides. D. M. Uz, who conducted surveys in Teos between 1980 and 1992, mentioned the existence of a very strong defensive wall extending east-west on Külahlıkır Hill, to the northeast of the Acropolis. Investigating the city’s necropolis on Külahlıkır Hill, Uz came across a 6th century BC Clazomenian type painted terracotta sarcophagus, as well as numerous fragments of terracotta sarcophagi and partially buried later stone sarcophagi. Because Sığacık (North) Harbour intruded further south in Antiquity, Külahlıkır Hill, which protected the Teos Peninsula by cutting its connection with the mainland, must have been included in the defence system.
Külahlıkır Hill was restudied in 2019 when limited excavations were carried out to investigate the defence systems of Teos; these revealed that the north-south wall on the hill was built independently from and in a different technique than the Hellenistic Wall that encircled the city. No material was discovered that could point to the necropolis on Külahlıkır Hill mentioned in previous research. During the current investigations, a north-south, 74.5 m-long fortification wall was identified at the top of Külahlıkır Hill (+25.10 m), on the eastern edge of a 17 m wide flat area. The wall was made of large rectangular blocks of local limestone and its preserved thickness varied between 1.70 m and 2.05 m
Archaeological map of Teos and its surroundings (Kadıoğlu, 2021, 25, Map 4)