Founded in 1253, the University of the Sorbonne was at the centre of the Latin Quarter's intellectual activity from the Middle Ages until 1968, when it was occupied by students and stormed by the riot police. The authorities then split the University of Paris into safer outposts, but the Sorbonne still houses the Faculté des Lettres. Rebuilt by Richelieu and reorganised by Napoleon, the present buildings date from the late 1800s, and have a labyrinth of classrooms and lecture theatres, as well as an observatory tower. The elegant dome of the 17th-century chapel dominates place de la Sorbonne; Cardinal Richelieu is buried inside. It's only open to the public for exhibitions or concerts.