Festungsberg is a mountain in the city of Salzburg, Salzburgerland, Austria. Its summit at about Template:Convert is the site of Hohensalzburg Castle.
The mountain is located in the south of the Altstadt or Old Town quarter. It forms the northern rim of the Berchtesgaden range within the Northern Limestone Alps.
Archaeological findings date back to the Celtic La Tène culture. The area was fortified during the days of the Roman above the city of Iuvavum until King Odoacer of Italy commanded to leave the Province of Noricum in 488. About 715 Bishop Rupert of Salzburg established the Benedictine Nonnberg Abbey at the eastern foot of the mountain. Archbishop Gebhard had a first castle built at the top during the Investiture Controversy about 1077. Formerly used for grassland or for vineyard cultivation by the monks of St Peter's Abbey, the slopes are nowadays mostly wooded.