article: Circle line (London Underground)
links: Farringdon station Hammersmith & City line District line Paddington tube station (Bakerloo, Circle and District lines) London and North Western Railway Great Western Railway River Thames Third rail London Passenger Transport Board Liverpool Street station Aldgate tube station London Underground London Underground C69 and C77 Stock City of London Edgware Road tube station (Circle, District and Hammersmith & City lines) Transport for London 7 July 2005 London bombings Rapid transit Alternating current London Overground Metronet