Highgate tube station is a London Underground station on Archway Road, Highgate, not far from Highgate Village in north London. It is on the High Barnet branch of the Northern Line, between Archway and East Finchley, in Travelcard Zone 3.
The present low-level station was built in the late 1930s as part of London Underground’s Northern Heights plan. It is just part of the planned station but the advent of the Second World War postponed parts of the project and eventually led to its cancellation. The low-level station was built directly below the existing high-level London & North Eastern Railway (LNER) station.
Text from Wikipedia, Highgate tube station