From Wiki.Kidzsearch.com:

“The Mezquita (Spanish for “mosque“) of Cordoba is a Roman Catholic cathedral. It used to be a mosque situated in the Andalusian city of Córdoba, Spain. [1] At first the site had been used for a temple, then a Christian cathedral. Under the rule of Islam, it was built as the second-largest mosque in the world. It is perhaps the most accomplished monument of the Umayyad dynasty of Cordoba. It changed into mosque in Middle Ages. [2]After the Spanish Reconquista, it was changed back into a church, and some of 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.”