On the Acropolis of Ancient Siphai (modern Halyki), pottery of several periods of prehistoric and historic times has been found sporadically, indicating a long period of habitation. The 4th cent.B.C. - when the citadel and apparently the town to the south o it were fortified - and the roman imperial times (1st-2nd cent. B.C.) are regarded as periods of floruit.

The fortification walls of the citadel which are preserved in a satisfactory length and height are strenghtened with 6 towers. Three gates exist, from which the main one is near the seashore. The walls are dated to te 4th cent. B.C. The citadel (acropolis) of Siphai belongs to the series of citadels at the Korinthian gulf like the one at Porto Germeno in Attica (ancient Aegosthena), Livadhostra (ancient Kreusis), Prodroms (ancient Korsiai), Zaltsa (ancient Boulis). Siphai was a port of Thespiai like Kreusis.