The Place du Châtelet is a public square in Paris, on the right bank of the river Seine, on the borderline between the 1st and 4th arrondissements. It lies at the north end of the Pont au Change, a bridge that connects the Île de la Cité, near the Palais de Justice and the Conciergerie, to the right bank. The name "Châtelet" refers to the stronghold, the Grand Châtelet, that guarded the northern end of the Pont au Change, containing the offices of the prévôt de Paris and a number of prisons, until it was demolished in 1802-10