Servian Wall The Servian Wall ( , ) was a defensive barrier constructed around the city of Rome in the early 4th century BC . The wall was up to 10 metres ( 32 . 8 ft ) in height in places , 3 . 6 metres ( 12 ft ) wide at its base , 11 km ( 7 mi ) long , and is believed to have had 16 main gates , though many of these are mentioned only from writings , with no other known remains . History . It is presumed that the wall is named after the sixth Roman King , Servius Tullius . Although its outline may go back to the 6th century BC , the currently extant wall was , it is estimated , built during the early Roman Republic , possibly as a way to prevent a repeat of the sack of Rome during Battle of the Allia by the Gauls of Brennus . Due to the ease with which the Gauls entered the city , it is conjectured that at some time previous to this , Rome had been forced by its Etruscan rulers to dismantle any significant prior defenses . Construction . The wall was built from large blocks of tufa ( a volcanic rock made from ash and rock fragments ejected during an eruption ) quarried from the Grotta Oscura quarry near Rome ' s early rival Veii . In addition to the blocks , some sections of the structure incorporated a deep " fossa " , or ditch in front of it , as a means to effectively heighten the wall during attack from invaders . Along part of its topographically weaker northern perimeter was an agger , a defensive ramp of earth heaped up to the wall along the inside . This thickened the wall , and also gave defenders a base to stand while repelling any attack . The wall was also outfitted with defensive war engines , including catapult s . Usage . The Servian Wall was formidable enough to repel Hannibal during the Second Punic War . Hannibal famously invaded Italy across the Alps with elephants , and had crushed several Roman armies in the early stages of the war . However , the wall was never put to the test as Hannibal only once , in 211 BC , brought his Carthaginian army to Rome as part of a feint to draw the Roman army from Capua . When it was clear that this had failed he turned away , without approaching closer than 3 miles from Rome , when a Roman army sallied out of the Servian walls and pitched a camp next to Hannibal ' s . However , during the Roman civil wars , the Servian walls repeatedly were taken . The wall was still maintained in the end of the Republic and the early Empire . By this time , Rome had already begun to grow outside the original Servian Wall . The organization of Rome into regions under Augustus placed regions II , III , IV , VI , VIII , X , XI within the Servian Wall , with the other sections outside of it . The wall became unnecessary as Rome became well protected by the ever expanding military strength of the Republic and of the later Empire . As the city continued to grow and prosper , it was essentially unwalled for the first three centuries of the Empire . However , when German tribes made further incursions along the Roman frontier in the 3rd century , Emperor Aurelian had the larger Aurelian Walls built to protect Rome . Present day . Sections of the Servian Wall are still visible in various locations around Rome . The largest section is preserved just outside Termini Station , the main railway station in Rome ( including a small piece in a McDonald ' s dining area at the station ) . Another notable section on the Aventine incorporates an arch 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 other known remains . )