22nd Street station is an underground trolley station in Center City Philadelphia that serves the SEPTA Subway–Surface Trolley Lines. Similar to 19th Street station, three blocks east of it, the station has two side platforms and a total of four tracks. The station serves only subway–surface trolleys on the two outer tracks; the Market-Frankford Line subway uses the two inner tracks and bypasses the station as it travels between 15th Street and 30th Street station.