The site is a small fort of purely military use extending in an area of just 3.000 sq. metres. It is encircled by a strong -mainly isodomic- defensive wall reinforced by rectangular towers and preserved in a very good condition. Only a small section of the wall to the west is constructed in polygonal masonry, in accordance with other major fortifications of Thesprotia, i.e. Elea or Dimokastro. It dates to the 5th century BC and is the oldest surviving fortification of Thesprotia, contemporary with the neighboring settlement on the Lygia peninsula, with which it is directly connected. In antiquity, the main entrance was on the south wall, oriented towards the settlement of the peninsula, while in the north wall there was a secondary small gate, which nowadays serves as a visitor entrance to the archaeological site.
The purely military nature of the site during the Classical and Hellenistic periods is evidenced by the absence of buildings declaring permanent habitation. Also indicative of the defensive character of the fort is an impressive rock-cut cistern for the collection and storage of rainwater, which is entirely carved into the rock and has a diameter of 13 meters and a depth of more than 5 m. In the vicinity of the tank there is a construction of large rectangular stone blocks, possibly a sanctuary or a fountain.
In one of the prominent rocks of the southeastern portion of the top of the hill there is a rectangular cutting, which both construction time and the purpose they serve still unknown.
A noticeable number of dry-stone enceintes and walls, dating to the ottoman period, attest for an extended and more systematic habitation of the site during that period. This is the period when a two-storeyed building was constructed right above the northern tower of the ancient fortification wall: the Tower (Pyrgos), to which the site owns its name.
The Tower of Pyrgos Ragiou belongs to the architectural type of ?koulia? or ?kula? which, along with the type of towerhouse, was quite common in the whole Balkan area during the ottoman period. It was a building used as a guardhouse - watchtower and for the accommodation of Agha (turkish guard) of the area. Owing to its defensive character, the building lacks entrances or other openings at the ground floor. The only entrance is situated at a higher level and was accessible via a stone stairway and a wooden drawbridge. Accordingly, the windows -square or arched- are small and absent from the ground floor. For the efficient confrontation of the enemy, there are gun slits on every wall, as well as an oil cruet right above the entrance. From that opening hot oil was poured down on the attacker.