Córdoba, Andalusia
The Romans occupied Córdoba in 206 B.C. The city was very important in the 900s CE as a famous center of Moorish art and culture.  The Mezquita de Córdoba is the city's chief landmark. It was built as a mosque (Muslim house of worship) in the 700s and was made into a Roman Catholic cathedral in 1238.  More than 1,000 pillars of stone including granite, onyx, marble and jasper support its arches.