sentences:  In the 19th century, portions of the Gothic walls and towers of the Cité de Carcassonne were restored, with some modification, by Eugene Viollet-le-Duc.He also rebuilt the Château de Pierrefonds (1393–1407), an unfinished medieval castle, making it into a neo-Gothic residence for Napoleon III.This project was incomplete when Napoleon III was overthrown in 1870, but can be visited today.