Shlisselburg (; ; ; ), formerly Oreshek (Орешек) (1323–1611) and Petrokrepost (Петрокрепость) (1944–1992), is a town in Kirovsky District of Leningrad Oblast, Russia, located at the head of the Neva River on Lake Ladoga, east of St. Petersburg. Population: The Shlisselburg Fortress and the town center are UNESCO World Heritage Sites. History Fortress The city was founded in 1323 with a wooden fortress named Oreshek () which was built by Grand Prince Yury of Moscow (in his capacity as Prince of Novgorod) on behalf of the Novgorod Republic in 1323. After a series of conflicts, a peace treaty was signed at Oreshek on August 12, 1323, between Sweden and Grand Prince Yury and the Novgorod Republic. In 1348 king Magnus Eriksson attacked and briefly took the fortress during his crusade in the region in 1348–1352. It was largely ruined by the time the Novgorodians retook the fortress in 1351. In 1478 the Novgorod Republic was absorbed by the Muscovy who immediately started to strengthen their border with Sweden. The existing small citadel was demolished and a new stone fortress with seven towers was constructed, which occupied almost the entirety of Orekhovy Island. In 1554–1555, during the Russo-Swedish war, the Swedes laid siege to the fortress, with no success. In response, Muscovites besieged Vyborg, with no success either. During the Livonian war, in 1582 Swedish troops led by Pontus De La Gardie almost captured the fortress. After a row of artillery fire they managed to break into one of the towers, but were later repelled by Muscovites. The fort was captured by Sweden in 1611 during the Ingrian War after nine months of siege, when the defenders lost every nine out of ten men. During the Ingrian Campaign of tsar Alexei Mikhailovich in June 1656 the fortress came under a siege by voevoda Potyomkin which lasted until November 1656 with no success. In 1702, during the Great Northern War, the fortress was taken by Russians under Peter the Great in an amphibious assault: 440 Swedish soldiers defended the fort for ten days before surrendering. (See Siege of Nöteborg (1702)). Peter renamed the fortress to Shlisselburg, a transliteration into the Cyrillic alphabet of Schlüsselburg. The name, meaning "Key-fortress" in German, which refers to Peter's perception of the fortress as the "key to Ingria". During the Imperial period the fortress lost its military role and was used as a notorious political prison. Immediately