Châtelet (French pronunciation: ​[ʃɑtlɛ]) is a station of the Paris Métro and Île-de-France's RER commuter rail service, located in the centre of medieval Paris, on the border between the 1st and 4th arrondissements. It serves RER A, RER B and RER D, as well as Line 1, Line 4, Line 7, Line 11 and Line 14 of the Paris Métro; it is the southern terminus of Line 11. The station is made up of two parts connected by a long corridor: Lines 7 and 11 under the Place du Châtelet and the Quai de Gesvre (site of the original medieval river port of Paris), next to the Seine; Lines 1, 4 and 14 towards Rue Saint-Denis and the Rue de Rivoli.