The ruins of Teos is 1 km south of Sığacık village, which is located 5 km away from Seferihisar district. According to some historians, Teos was founded in 1050-1000 BC. Athamas, the son of Dionysus, is known as the founder of the city. Teos is one of the 12 Ionian cities and the Temple of Dionysus, just off the road, was built by the Hermogenes of Prien in the early 2nd century BC. It is the largest temple built in the name of Dionysus in Anatolia. It was repaired frequently during the Roman Empire, but was still damaged by earthquakes.

500 m. northwest one can see Hellenistic walls, Theater, Acropolis and Gymnasium. From the inscriptions it is understood that there were 3 classrooms in the Gymnasium; and also 63 teachers, two of whom were sports teachers and another was music teacher. The Ionian Actors Association was first established in Teos in the late 3rd century BC and the actors, using Teos as their base, had performed in various places. There are works of Hellenistic and Roman periods in Teos. Among the most important of these are the Temple of Dionysus, the Agora, the Theater, the Odeon, the Walls and the Harbor.

Teos, the main source of sea trade, had two harbors, one small and the other big.