Backside of What?

Well this is again from Paris but I really didn't like the front side of this cathedral so I went to the back and discovered this shot. Ironically my dad, when he saw this shot, told me that he also took the same shot when he was in Paris...like father like son. Although not always a good thing, this time I'd say it is. Another print if anyone can tell me what the cathedral's name is, oh and Kailen can't answer because she was with me.