Greater London is an administrative area and ceremonial county in southeast England that covers the United Kingdom capital of London. The administrative area was created on 1 April 1965 and has been the London region since 1 April 1994. It comprises the City of London and 32 London boroughs, of which 12 are Inner London and 20 Outer London boroughs.
Greater London includes the most closely associated parts of the Greater London Urban Area and their historic buffers and includes, in five boroughs, significant parts of the Metropolitan Green Belt which protects designated greenfield land in a similar way to the city's parks. The closest and furthest boundaries are with Essex to the northeast between Sewardstonebury next to Epping Forest and Chingford and with the Mar Dyke between Bulphan and North Ockendon. Greater London is also bounded by Hertfordshire to the north, Berkshire and Buckinghamshire to the west, Kent to the southeast and Surrey to the south and southwest. The highest point is Westerham Heights, in the North Downs and on the boundary with Kent, at 245 m (804 ft). Central government has implemented small boundary changes. The greatest were the 1969 transfers of Farleigh to Surrey and Knockholt to Kent. Others have included exchange of two Thames islands with Surrey and adjustments during the 1990s to parts of the boundaries of three boroughs near the M25. The only part of Greater London outside the motorway is North Ockendon, the furthest land unit from its centre. The majority of Greater London forms the London low emission zone.
The London postal district does not cover all of Greater London.