The narrow and often steep granite-paved streets of Cagliari’s Castello District are a reminder of a bygone age when the town was dominated at first by Pisans, and later by the Aragonese. Built from white limestone, the walls and towers of the Old Town shimmer in the sun and are a magnificent sight, especially if you are lucky and approach the city from the sea, as the English novelist D.H. Lawrence did in 1921 when he described the Old Town as looking like a "Jerusalem without trees".