I want to know the answer to the following question:
What other famous French cathedral did Viollet-le-Duc work on?
All the background I'm provided with is that "He effected vigorous restoration of crumbling detail of French cathedrals, including the Abbey of Saint-Denis and famously at Notre Dame de Paris, where many of whose most "Gothic" gargoyles are Viollet-le-Duc's.". Is that enough to answer the question?