As beautiful as the large cathedrals in Europe are, many are showing their age and the results of erosion from the elements and pollution. Many of the churches were made out of limestone, since it was available and relatively easy cut and carve. But because it is a softer stone, it is more likely to wear down faster.
The Rouen Cathedral was in the midst of repairing some of the pinnacles when we visited last July. Inside they had placed some of statues of saints from the exterior facade that were too weathered or in danger of collapse. Occasionally, when repairing these types of structures, a replacement piece will be created to take the place of the original. Notice how they are all looking down, since they were up high on the side of the church.