Their perimeter is 2.140m. they have got eighty-five cylindrical towers, four doors crowned by Roman arches and there are some towers on their sides (from the original eighty five towers, only sixty-two of them are well preserved, eight are partially in ruins and five have disappeared. We can use five stairs and a ramp to climb up the walls. They are near the doors. The first stairs that were discovered were the ones situated between the "Puerta del Postigo" and the "Puerta del Obispo Aguirre". They have two parts situated along the walls of the walk. They contain the biggest number of steps. In the photograph, some of the cylindrical towers and one of the doors, crowned by a Roman arch can be seen.

The walls were used to defend the city against enemies and also as a defense against the winds. The walls are one of the best preserved archaeological remains from the Roman times. There were other more modern approaches at "Mina's Door", some of them have disappeared, but others have been rebuilt. Nowadays all these missed approaches are on a plan. The other six approaches still remain.