One of the most recognizable religious structures in France (probably second only to Notre Dame) is the abbey and cathedral atop Mont St Michel. This is on a small tidal island off the coast of Normandy. Arthur Gugick present this beautiful microscale recreation. You can see more great religious architecture at GodBricks.
By the way, Arthur wrote that this is one of seven world landmarks that he previously thought would be impossible to faithfully present in LEGO. I'd love to know the other six, and hope he tries his hand at those as well.