Córdoba is an old city, having passed through Iberian, Roman, Visigothic, Moorish and Christian rule. The outstanding feature of Córdoba is La Mezquita-Catedral, or "Mosque-Cathedral." Beginning in the year 785, on the site of a Visigothic church, the mosque was built with 11 large aisles and a huge floor space. Over the next two hundred years, a minaret was added, the mosque was greatly expanded in size, and the number of aisles was increased to 19. The "Great Mosque" became the most important mosque of western Islam, and one of the largest anywhere. In the 16th century, a cathedral was built inside and at the center of the mosque, amid the aisles. In addition, the minaret was altered, but many of the Moorish features were preserved, including the large open courtyard called the Patio of the Orange Trees. The cathedral occupies only about 10% of the floor space of the mosque.