The Castle is found on the top of a hill overlooking the town and was used to protect the town from the mainland and the sea. It was initially built in the 11th century by the residents of Parga to protect their town from pirates and the Turks. In the 13th century, as their control of the region increased, the Venetians rebuilt the castle to fortify the area. In 1452, Parga and the castle were occupied by the Ottomans for two years during which time part of the castle was demolished. 1537, Ottoman admiral Hayreddin Barbarossa burnt and destroyed the fortress and the houses within.
Before the reconstruction of the castle in 1572 by the Venetians, the Turks demolished it once again. The Venetians rebuilt it for the third and last time creating a perfect, strong fortress that stayed impregnable until 1819, despite attacks, especially by Ali Pasha of Ioannina, who besieged them from the castle of Agia-Anthousa. The Venetians created a perfect defence plan which they combined with the natural fortification made the fortress. Outside the castle eight towers placed in different positions completed the defence. Inside the narrow space of citadel there were 400 houses, positioned so that they occupied only a small space far away from the seaside. From this castle the free-besieged population of Parga and Souli fought epic battles, retaining their freedom for centuries. From the faucet “Kremasma” the tanks of the castle and the houses were provided with water. The castle for its provision used the two bays of Valtos and Pogonia. When Parga was sold to the Ottomans, Ali Pasha enhanced it even more by placing both its harem and Turkish bath at the top. This radically improved the rooms of the castle. On the arched gate at the castle entrance, on the wall, you can see the winged lion of Agios Markos, the name “ANTONIO BERVASS 1764”, emblems of Ali Pasha, two-headed eagles and relative inscriptions. Archways, gun emplacement rooms, supplies lodges, strong bastions with gun safe boxes, safe boxes of small arms, secret passage to the sea, barracks, jails, warehouses and two block-houses at the last defense line: prove the perfection of the defense plan, which along with the natural fortification, made the fortress unconquered.
Source: wikipedia.org