The Underground has a long tradition of high quality station architecture, and has consciously promoted its best new environmental design through posters since the 1920s. More than 50 pre-war stations, including many designed by Charles Holden, are now listed
buildings. New developments, station modernisation and openings, artistic decorative schemes and special exhibitions at stations such as Charing Cross (Embankment), which had its own display gallery until the 1960s, have all been featured in posters.