Passage d'Harcourt, near the Collège d'Harcourt, a Medieval college of the Sorbonne built by the famous Anglo-French Harcourt familly during the Middle Ages. This passageway was demolished due to Haussmann’s obsession with straight avenues (Avenue Saint-Michel in this case).
The Château d'Harcourt is the cradle of the Harcourt family. The first stone castle here was built by Robert II d'Harcourt, a crusader companion of Richard I (the Lionheart). Harcourts appear later among the most important barons of Normandy. Jean II d'Harcourt was a Maréchal de France.
The castle is one of the best preserved castles in the country and boasts the oldest arboretum in France.