The remaining buildings from previous ages, especially from the Safavid and later periods, each has an important cultural, religious or military and political significance. Among the historic buildings, The Forg Castle, is one of the most beautiful castle with a location and architecture that is unique. This castle is located in a village with the same name about 90 kilometers from Birjand. The original parts of this Castle dates to Nader Shah Afshar (ruled 1732-1749AD). The interior installations have three main parts, i.e. a section for servants and services, a military section and the main part for the rulers of the castle. The Forg Castle is on top of a stone cliff with 18 towers. After the passing of centuries, it has kept its stature in the history of Birjand and witnessed the various historic events.