When Heinrich Schliemann looked to Homer's Iliad as a reference to find Troy, it was clear that he needed to find the famous Trojan citadel, the most distinguishable feature of the city. Finding the wall would really make the epic poem come to life, as one could imagine Hector being dragged around the walls of Troy, or Andromache watching over the city from the walls.
Homer describes a large citadel surrounding Troy, including vast wooden gates at the entrance to the city. He describes the walls as 'well-founded’ and ‘strong-built’, and these claims are proven by the walls ability to withstand a ten-year siege.
In fact, the walls never did fail or crumble; instead, the Trojans were tricked by the Greeks with an ambush using a wooden horse, allowing them to sneak into the city.
Schliemann discovered city walls on the 6th level of excavations, Troy VI, which provided evidence that Hisarlik was the site of Troy. Initially, scholars were skeptical because the site of Hisarlik seemed too small to be the commercial or trading centre that Homer described, but later excavations by Manfred Korfmann demonstrated that as many as 6,000 people may have lived there.
This showed scholars that the citadel unearthed by Schliemann could have held enough people to be the lively city of Troy.
Altogether, excavations have uncovered 23 sections of the defensive walls around the citadel, eleven gates, a paved stone ramp, and the lower portions of five defensive bastions.