The city walls were planned, designed and constructed by three empires in their relative ascendancies. When the Moors sailed over from Africa and conquered Iberia from the Visigoths they began at Gibraltar. The Fortress of Gibraltar has evolved over centuries and as such its walls have seen development from bow and arrow defences to gunpowder, muskets and cannonshot. Halfway up the northern slopes of the Rock is Gibraltar’s medieval castle complex complete with its Tower of Homage, Inner Keep and Quasbah.
Running down from the Qasbah to what was the bay is the Flanking wall. This connects to Grand Battery and North Bastion completing the Northern defensive perimeter. The Line Wall guarded the seaward western flank of the city. Through reclamation the city wall is now landlocked but waves would have lapped at the foot of these monumental walls. The Line Wall can be traversed by car or on foot and many of the bastions offer interesting points of note, along the route south, to South Bastion. After 1540 at the Southern extremity of the old City the Spanish built the Charles V wall to inhibit Barbary pirate raids. This wall can be seen making its way to the summit of the Rock and can also be walked as it forms a large staircase.