The Mezquita-Catedral is quite spectacular a literal and figurative clash of cultures. A serene open mosque, sunlight streaming in from all 4 sides, was raped architecturally when invading and conquering Christians, constructed not one but two cathedrals inside the open plan mosque, bricking up the huge open gates from the adjacent garden. It is still something at which to marvel.

This is the bell tower of the cathedral which was constructed around the minaret tower of the mosque, so to completely hide it.

Part of the mosque

The Christian cathedral within the walls of the mosque