Great Mosque of Córdoba, Spain

The earliest parts of the Great Mosque of Córdoba, Spain, were built on the site of a Christian church by the Umayyad ruler Abd al-Rahman I in 784–786. The structure underwent several enlargements in the 9th and 10th centuries. During one of these enlargements a richly decorated mihrab (a niche in a mosque pointing in the direction of Mecca) set behind an intricate arch was added. Another remarkable feature of the mosque is the hypostyle hall consisting of approximately 850 columns made of porphyry, jasper, and marble supporting two-tier horseshoe arches. Most of the columns and capitals were recycled from earlier buildings.