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
Timeline of the London Underground eventually consolidating under the single ownership of the Underground Electric Railways Company of London (UERL), with lines stretching across London. In 1933, the UK Government amalgamated the UERL and the Metropolitan Railway as a single organisation, named the London Passenger Transport Board. The London Underground has since passed through a series of administrations, expanding further by the construction of new extensions and through the acquisition of existing main line routes, culminating in its current form as part of Transport for London, the capital's current transport administration, controlled by the Greater London Authority. This timeline lists significant dates in the history