The A1 in London is the southern part of the A1 road. It starts at Aldersgate in the City of London, passing through the capital to Borehamwood on the northern fringe of Greater London, before continuing to Edinburgh. The road travels through the City and three London boroughs: Islington, Haringey and Barnet, which include the districts of Islington, Holloway, Highgate, Hendon and Mill Hill, and travels along Upper Street and Holloway Road, crossing the North Circular Road in Hendon, a district in the London Borough of Barnet.