Built in murus dacicus style, the six Dacian Fortresses of the Orăștie Mountains, in Romania, were created in the 1st centuries BC and AD as protection against Roman conquest, and played an important role during the Roman–Dacian wars.

Sarmizegetusa Regia was the capital and the most important military, religious and political centre of the Dacians before the wars with the Roman Empire. Built on top of a 1200 m high mountain, the fortress, consisting of six citadels, was the core of a strategic and defensive system in the Orăștie Mountains.