The Mezquita (Spanish for "mosque") of Cordoba is a Roman Catholic cathedral and former mosque situated in the Andalusian city of Córdoba, Spain. Under the rule of Islam, it was built as the second-largest mosque in the world. After the Spanish Reconquista, it was transformed into a church, and partly the Islamic columns and arcs were replaced by a basilica in early Baroque style. Today it houses the main church of the diocese of Cordoba in Spain.

The construction of the Mezquita started in approximately 600 A.D. as a Christian Visigothic church. Later, under Moslem occupation, the Mezquita (originally the "Aljama Mosque") was reworked for over two centuries to refashion it as a mosque, starting in 784 A.D. In 1236, Cordoba was recaptured from the Muslim army by King Ferdinand III of Castile and the mosque was reconsecrated a Christian church.

The building is most notable for its giant arches, with over 1,000 columns of jasper, onyx, marble, and granite. http://en.wikipedia.org/wiki/Mezquita