The rocky hill of Kastron was first settled at the end of the Neolithic era and was continuously inhabited until the 5th cent.A.D. although in the meantime it was destroyed and abandonned for some time. The preserved structures and the fortification date to the archaic, classical and hellenistic times (6th - 1st century. B.C.).

The fortification walls were always visible and Korsiai are mentioned by travelers. Excavation research was conducted in the early ΄80s by a canadian archaeological mission.

The most important monuments of Acropolis of Ancient Korsiai are:

The existing fortification walls, which protect the acropolis and the town of ancient Korsiai. They were built in the 4th cent. B.C. Two building phases can be discerned.

The Temple of Hera, rectangular building to the north of the acropolis, outside the fortifications. The earliest evidence for the cult of Hera at Korsiai dates to the Archaic period (6th cent. B.C.).

The so-called "industrial area" which was found on a flat terrain to the south of the town outside the walls. What remains comprises mainly cisterns of various sizes. Considering also the big number of weights found it is deduced that the area was a textile workshop.