The Notre-Dame Cathedral in Rouen. With a height of 151m, the Notre-Dame Cathedral in Rouen was the highest building in the world from 1876 to 1880.
Notre Dame, Paris. My favorite part was the rose window. A fellow tourist asked our guide at what time the buttresses start to fly. Even worse, when we were in Seville, Spain someone from that tour inquired whether all the gold in the cathedral was for Jesus. He could not believe it.