This is the original Mihrab [link] of the Grand mosque in Cordoba(now a cathedral), its absolutely stunning and conveys a very Ummayad architectural feel to it.
The golden mosaic remind you of the grand ummayad mosque in Damascus, which is interesting because the man who started building this mosque was Abd ar-Rahman I who was the last Ummayad prince and was kicked out of Damascus by the fatamids when they took power, he moved to Cordoba and swore to make that city more grand in every detail than his lost Damascus.