The Archaeological Site of Kleidi Samikos is located at the western slopes of Mount Lapitha, southeast of the village of Kato Samikos in Ilia. It is part of the wider archaeological complex of Kato Samikos, which includes the prehistoric acropolis on Kleidi Hill and the Classical Age acropolis on Elliniko Hill.​

The prehistoric acropolis on Kleidi hill is surrounded by cyclopean walls and shows evidence of habitation from the Middle Helladic (2100/2000-1600 BC) to the Late Helladic Period (1600-1100 BC).​

Recent excavations at Kleidi Samikou, as part of a five-year research program (2022-2026), revealed important evidence about a monumental building discovered in 2022. This building, probably a temple, dates back to the 6th century BC and has an unusual floor plan with two main halls and a smaller one in the northwest section. In the first hall, the bases of two columns were found, indicating the existence of a colonnade along the axis of the building. ​

Excavations continue with the aim of further investigating the topography of the area and locating the sanctuary of Poseidon, mentioned in the Iliad.