Porte de Montreuil is a station on line 9 of the Paris Métro. The station has four tracks, two of which are sidings, and is quite impressive in scale. It is named after the Porte de Montreuil, a gate in the nineteenth century Thiers wall of Paris, which led to the town of Montreuil. Flea markets are held on the glacis (the sloping bank in front of a wall) of the fortifications. The station was opened on 10 December 1933 with the extension of the line from Richelieu - Drouot.