The highlight of every visit to Gjirokastra is a visit to the massive castle on the hill overlooking the town. The first large fortress was built here in the 12th century, though most of what is visible today dates from the 19th century, when governer Ali Pasha of Tepelene added the final fortification walls, the clock tower, and a 10-kilometre-long aquaduct to privide the garrison with fresh water. In the 20th century it was used as a terrible prison by a succession of repressive regimes before it closed in 1968.
Recently renovated, the bowels of the castle houses an artillery gallery and the new Gjirokastra Museum which highlights the history of the city. In the former prison you can view the inmate's cells and the armaments collection, which focuses on military hardware of yesteryear and the Partizan resistance in World War 2. The best exhibit in the castle is a slowly desintegrating US Airforce jet, a Lockheed T-33, which made an unfortunate emergency landing in Tirana in 1957. The regime claimed that the plane was spying on Albania and was forced down, though it seems that it simply had technical problems - either way, the pilot was sent home and the plane was gratefully used for propaganda purposes. The castle courtyard has a stage that hosts a folklore festival every four years. The ramparts leading up to the quaint clocktower offers the best views over the city and the surrounding mountains.