The Piccadilly line is a deep-level London Underground line which runs between the west and the north of London with 53 stations on the line. The line serves Heathrow Airport, and some of its stations are near tourist attractions in Central London such as King's Cross, Piccadilly Circus and Buckingham Palace. It has two western branches which split at Acton Town, with the main one towards Heathrow Airport terminals and the other northern branch towards Uxbridge. The District and Metropolitan lines share some sections of track with the Piccadilly line. The line is printed in dark blue on the Tube map. It is the sixth-busiest line on the Underground network, with nearly 218 million passenger journeys in 2019.