Canary Wharf is a London Underground station in the Canary Wharf commercial estate; it is on the Jubilee line, between Canada Water and North Greenwich. The station, located in Millwall, is in Travelcard Zone 2 and was opened by Ken Livingstone setting an escalator in motion on 17 September 1999 as part of the Jubilee Line Extension. Over 40 million people pass through the station each year, making it second busiest on the London Underground outside Central London after Stratford, and also the busiest that serves only a single line.