While the absolute gem in the crown of the most Moorish of Spanish cities is the famous Alhambra, a towering stronghold located on top of the Assabica hill, the city walls are equally interesting as an example of a great Muslim fortification against the Christian assault of the city. The original walled perimeter of the city dates back to the 11th Century and ranged from the banks of the river Darro to the edges of the original Arab settlement of the Albaicín neighbourhood, but was subsequently expanded in the 12th and 13th Centuries. Although much of the construction is lost nowadays, historians estimate it spanned more than 8,000m. The remains of several of its gates can still be admired in a walk around the old part of Granada, particularly along the emblematic Carrera del Darro river walk. (Xurxo Lobato/Getty Images)