Porte d'Orléans is a station of line 4 of the Paris Métro and a stop on tramway line 3a. It is situated in the 14th Arrondissement, in the quartier of Petit-Montrouge. The station is the former southern terminus of line 4. A terminal loop was provided at the station for trains to turn around to return north towards Porte de Clignancourt. Passengers used to disembark at the arrival platform and then the train proceeded empty via the loop to the departure platform. The extension to Mairie de Montrouge modified the layout of the station, the northbound platform was extended toward the track coming from the former terminal loop to add a new entrance.