Airports of London Heathrow, more than Paris and Frankfurt combined, and Heathrow is the European terminus for 11 of the 25 busiest north Atlantic routes. The busiest long-haul route in the world is between London (Heathrow and Gatwick) and New York (JFK and Newark), with a total of 3,898,460 passengers travelling between the two cities in 2011. Airports of London The metropolitan area of London, England, United Kingdom is served by six international airports and several smaller airports. Together, they make the busiest airport system in the world by passenger numbers and the second-busiest by aircraft movements. In 2016, the six airports handled
London Underground infrastructure London Underground infrastructure The infrastructure of the London Underground includes 11 lines, with 270 stations. There are two types of line on the London Underground: services that run on the sub-surface network that is just below the surface and use larger trains, and the deep-tube lines, that are for the most part self-contained and use smaller trains. Most of the lines emerge on to the surface outside the central area. The oldest trains running on the Underground were introduced in 1972. The Underground is electrified using a four-rail system, the DC traction supply being independent of the running rails. Planned