La Mezquita, Cordoba

This is a mosque built in Cordoba during the Moorish habitation in Spain in the 9th and 10th centuries. It was taken back in the 1200s by the Christian reconquista of Spain. Soon afterwards, the King Ferdinand III authorized the building of a cathedral inside the mosque, which he later regretted saying, "You have destroyed something unique to make something commonplace." The cathedral in the center of the building does take away the long viewing angles, but nevertheless, it is a beautiful structure.