The Ali Pasha Fortress, located in a sheltered bay - originally on an island, now on a peninsula - of Porto Palermo, is also known as the "Castle of Porto Palermo". It is said to have been built around 1800 on a Venetian ruin. The builder, the Ottoman Pasha of Albanian descent named Ali Pasha Tepelena, ruled large parts of Ottoman Albania and northern Greece.
Built from limestone, the walls are sometimes more than 3 meters thick, ensuring pleasant temperatures inside during the hot summer months. The complex with a triangular floor plan and three round corner bastions is similar to the fortress in Butrint. It was in a military restricted area until 1989 and was used by the Albanian military during the communist era. In the immediate vicinity of the fortress is the country's only submarine bunker, which was of great strategic importance for Albania during communist times and was therefore also used for military purposes until 1989.