The Hohensalzburg Castle built in 1077 by Prince Gebhard I of Helffenstein ,stands on a rocky outcrop approximately 394ft (120m) above the city. The present-day fortress was largely rebuilt in the early 16th century by Archbishop Leonhard Von Keutschach who added the grand state apartments. Today it is considered to be the largest fortification in Europe, covering an area of over 14,000 mē. The Fortress is federally owned, although it has been under the Province of Salzburg's administration since 1953.

Hohensalzburg Castle (Wikipedia)