Airports of London cannot be expanded due to the docks on either side. It is also the only airport serving London which does not operate at night. A light rail service from London City Airport DLR station, which adjoins the terminal building of London City Airport, links it to the financial district of the City of London at Bank and Monument stations, which offer interchanges with London Underground. Located in the London Borough of Hillingdon, Heathrow is by far the largest of London's airports and considered the main gateway into the United Kingdom for non-European visitors. Heathrow has four terminals and two parallel
National Airports System National Airports System Canada's National Airport System (NAS) was defined in the National Airports Policy published in 1994. It was intended to include all airports with an annual traffic of 200,000 passengers or more, as well as airports serving the national, provincial and territorial capitals. All airports, with the exception of the three territorial capitals, in the NAS are owned by Transport Canada and leased to the local authorities operating them. As of 1994, the 26 NAS airports served 94% of all scheduled passenger and cargo traffic in Canada. Due to very close proximity to the Province of Newfoundland, the