Many of the photos here come from either the Mesquita or the Alcazar. Both stand on older ruins - the Mesquita, on a Roman fortress and Visigoth church; the Alcazar, on another Roman fortress. The existence of these ruins, and the fact that the materials were recycled by the Moors, explains how the original Mesquita was built in less than a year - a remarkable feat, even by today's standards. More impressive is the fact that, as the Mesquita was expanded, it eventually was able to hold up to 40,000 worshipers, the most for any Western mosque, and a truly fantastic number. The place is enormous - hence its ability to contain an entire cathedral inside it and still have room left over to show the look of the original mosque, as well as Roman and Visigoth ruins and the contents of the cathedral's treasury (lots of golden chalices and whatnot). I've also included a section on the Medinat al Zahra, short-lived city from around the year 1000 that ended up as a source of materials for the Mesquita.