City Thameslink is a National Rail station in the City of London. The platforms are underground, with a southern entrance on Ludgate Hill just off Ludgate Circus, and a northern entrance on Holborn Viaduct. It is in Zone 1, between Blackfriars and Farringdon, on the Thameslink route. It was the intended location of Ludgate Circus station on the Fleet Line (now Jubilee Line) until that project was abandoned in the late 1970s. Although a through station, for ticketing purposes it is considered a central London railway terminus for journeys to and from the south.