Underground station, and former railway station, on the Northern Line in Travelcard Zone 5.

It was opened by the Great Northern Railway on 1 April 1872, on the site of the Barnet Fair. It was transferred to London Underground as part of the "Northern Heights", underground services beginning 14 April 1940. from the pre-LT era.

More information on the Wikipedia page [1]. The TfL page is [2].