Shlisselburg (Russian: Шлиссельбу́рг, IPA: [ʂlʲɪsʲɪlʲˈburk]; German: Schlüsselburg; Finnish: Pähkinälinna; Swedish: Nöteborg), formerly Oreshek (Орешек) (1323–1611) and Petrokrepost (Петрокрепость) (1944–1992), is a town in Kirovsky District, Leningrad Oblast, Russia, located at the head of the Neva River on Lake Ladoga, 35 kilometers (22 mi) east of St. Petersburg. Population: 13,170 (2010 census); 12,401 (2002 census); 12,589 (1989 Soviet census).
The Shlisselburg Fortress and the town center are UNESCO World Heritage Sites.