Servian Wall
The Servian Wall (; ) was an ancient Roman defensive barrier constructed around the city of Rome in the early 4th century BC. The wall was built of volcanic tuff and was up to in height in places, wide at its base, long, and is believed to have had 16 main gates, though none have survived, and enclosed a total area of 608 acres. In the 3rd century AD it was superseded by the construction of the larger Aurelian Walls as the city of Rome grew beyond the boundary of the Servian Wall.