Gjirokastra is known as "The City of Stone". The main object is the city fortress, named the Fortress of Argjiro – the renowned story of the famous princess Argjiro gave rise to the name “Argjirokastro”, given to the city in 1336. Gjirokastër Castle is situated at an height of 336m. The castle dominates the town and overlooks the strategically important route along the river valley. It is open to visitors and contains a military museum featuring captured artillery and memorabilia of the Communist resistance against German occupation, as well as a captured United States Air Force plane to commemorate the Communist regime's struggle against the "imperialist" western powers.