Murus Dacicus

After each layer of the outer walls was completed, the gap between them would be filled with gravel and rocks cemented together with clay and compacted (cf.

Due to its higher flexibility, this structure had a distinct advantage over the 'classical', solid dry stone wall (as seen, e. g., in the cyclopean and ashlar walls in Mycenae): a higher capability of shock absorption and dissipation of kinetic energy from an incoming projectile thrown by a siege weapon.

However, archaeological and historical evidence suggests that the wall might have been topped by a wooden palisade instead of stone battlements, which had the obvious disadvantage of being vulnerable to fire.

A typical wall for the late period, hastily built in the years between the two Dacian Wars (when Dacia had to rebuild, repair, enlarge or reinforce the defenses of many of its key fortresses), would be about 3–4 meters thick and 10 m tall, an outstanding achievement in the given conditions.

The Dacian Fortresses of the Orăştie Mountains, UNESCO World Heritage Sites are examples of citadels built using this method.