Northwood is an aboveground station London Underground in the London Borough of Hillingdon. It lies in the Travelcard Zone 6 on the Greenlane. The station served by the Metropolitan Line station was used in 2013 of 2.28 million passengers. The station is located on the four-track section between Harrow-on-the-Hill and Moor Park. Only the two northern tracks have side platforms, in these keep local trains of the Metropolitan Line. Express trains of the Metropolitan line and all trains of the railway company Chiltern Railways pass through the two southern tracks without stopping. Single from London forth coming trains call in Northwood, but further north usually only during construction work or malfunctions. The opening of the station took place on 1 September 1887 by the Metropolitan Railway (predecessor of Metropolitan Line). On January 5, 1925, the section Harrow-on-the-Hill was - Rickmansworth electrified. In 1962, the distance between Northwood Hills and the branch was north of Moorpark, a second double track.