Sarmizegetusa was the most important Dacian military, religious and political center. Erected on top of a crag 1200 meters high, the fortress was the core of the strategic defensive system in the Orastie Mountains, in Romania, comprising six citadels.
The fortress, a quadrilateral formed by massive stone blocks (murus dacicus), was constructed on five terraces, on an area of almost 3 hectares. Sarmizegetusa also had a sacred precinct -- among the most important and largest circular and rectangular Dacian sanctuaries the famous Circular Calendar Sanctuary is included.
The civilians lived around the fortress, down the mountain on man-made terraces. Dacian nobility had flowing water, brought through ceramic pipes, in their residences. The archeological inventory found at the site shows that Dacian society had a high standard of living.
The Dacian capital reached its acme under Decebalus, the Dacian king defeated by the Roman Empire after two wars (101-102 and 105-106), led by Emperor Trajan. After the defeat of the Dacians, the conquerors established a military garrison there. Later, the capital of Roman Dacia was named after the Dacian capital - Colonia Ulpia Traiana Augusta Dacica Sarmizegetusa, established 40 km far from the ruined Dacian capital.
- Sarmizegetusa is also the name of a commune in modern day Romania, in the Tara Hategului depression, Hunedoara county, where the ruins of Colonia Ulpia Traiana Augusta Dacica Sarmizegetusa are located.