Visited in April 2014. The structure is amazing! The forest of pillars with the double arches reminiscent of the Arabian date palms..you feel like you are walking in a never-ending cool forest. Gives you a feeling of eternity - a hallmark of Muslim art/architecture, where patterns are repeated in seemingly endless ways to give the observer a sense of the eternal life to come after this temporal earthly existence. The sight was a Roman temple, then a church and when the Muslims took over Cordoba they first worshiped side by side with the Christians. Then the need for a mosque was great (as the Muslim population grew) so they bought it from the Church (this is documented...it was not a forceful taking-over) and then constructed this masterpiece. Many caliphs added to it and enlarged it. The Mihrab (prayer niche) is still preserved. Upon the reconquest, the Catholics wanted to tear it down as was every other jamia (main) mosque in every city that was taken over. But the people of Cordoba were so fond of the building they protested. So they built a cathedral in the center. It's a strangely interesting juxtaposition of Christian and Muslim art. A must visit place. You can lose yourself there