Classified a UNESCO World Heritage site in 1997, the famous medieval city of Carcassonne has 52 towers that testify to its rich history and provoke the wonder of the thousands of visitors it attracts every year. The architectural renovations of Viollet-le-Duc who have played an indispensable role in the conservation of the city in its exceptional state up to this day, have however been the origin of many polemics, especially because of the conical roofs in slate of the towers of the city.