The walls that encircle Kaleiçi are a palimpsest of two thousand years of city history. Originally built by the Attalid kings of Pergamon, they were raised, repaired, and modified by every subsequent ruler of the city — Roman, Byzantine, and Seljuk — each adding their layer to the mix. Much of the circuit still stands, and walking along the outer face of the walls at the southern edge of the old town gives a good sense of their scale.
Hadrian's Gate, at the northern entrance, is the most dramatic surviving element, but the tower ruins along the southern cliff edge and the stretches of wall visible from Karaalioğlu Park are also worth examining. Several sections have been partially restored; others are pleasingly ruinous.