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, of which only one or two have survived, and enclosed a total area of . In the 3rd century AD it was superseded by the construction of the larger Aurelian Walls as the city of Rome grew beyond the boundary of the Servian Wall. History. The wall is named  after the sixth Roman King, Servius Tullius. The literary tradition stating that there was some type of defensive wall or earthen works that encircled the city of Rome dating to the 6th century BC has been found to be false. The main extent of the Servian Wall was built in the early 4th century, during what is known as the Roman Republic. Construction. The Servian Wall was originally built from large blocks of Cappellaccio tuff (a volcanic rock made from ash and rock fragments that are ejected during a volcanic eruption) that was quarried from Alban Hills volcanic complex. This  initial wall of Cappellaccio tuff was partially damaged and in need of restoration by the late 390s (either because of rapid disintegration or damage sustained after the Sack of Rome in 390 BC). These reparations were done using the superior Grotta Oscura tuff which had become available after the Romans had defeated Veii in the 390s. This tuff was quarried by the vanquished Veientines. In addition to the tuff blocks, some sections of the structure incorporated a deep "fossa", or a ditch, in front of the wall, as a means to effectively heighten the wall. This second iteration of the  wall containing Grotta Oscura tuff is dated by Livy to have been completed in 378 BC. Along part of the topographically weaker Northern perimeter was an agger, a defensive ramp of earth that was built up along the inside of the Servian Wall. This effectively thickened the wall and also gave the defenders of Rome a base to stand while repelling an attack. The wall was also outfitted with defensive war engines, including catapults. Usage. The Servian Wall was maintained through the end of the Late Republic and into the Roman Empire. By this time, Rome had already begun to  outgrow the original boundaries of the Servian Wall. The Servian Wall became unnecessary as Rome became well protected by the ever-expanding strength of the field armies of the Republic and of the later Empire. As the city continued to grow and prosper, Rome was essentially unwalled for the first three centuries of the Empire. Expanding domestic structures simply incorporated existing wall sections into their foundations, an example of which survives in the Auditorium of Maecenas. When German tribes made further incursions along the Roman frontier in the 3rd century AD, Emperor Aurelian had the larger Aurelian Walls built to  protect the city of Rome. Present day. Several sections of the Servian Wall are still visible in various locations around the city of Rome. The largest section is preserved outside the Termini Station, the main railway station in Rome – including a section in a McDonald's dining area at the station. Another notable section on the Aventine Hill incorporates an arch that was supposedly for a defensive catapult from the late Republic. Gates along the Servian Wall. The following lists the gates that are believed to have been built, clockwise from the westernmost. (Many of these are inferred only from  writings, with no known remains.)