Greater London isn't in any county. It is its own Metropolitan Authority.
London is a part of Greater London county. UK does not have states or provinces, however, instead we have county.
In the borough of Merton, Greater London, England.
London is not a central county in England, it is in the South East of the country. Central London is not a county, but is within the county of Greater London.
Twickenham is in the ceremonial county of Greater London. Twickenham used to be in the county of Middlesex until that county was abolished and Twickenham was absorbed into Greater London.
Croydon is in the county of Greater London.
It isn't in a county. Greater London is its own administrative area.
Greater London
The City of London is part of the Metropolitan County of Greater London. http://en.wikipedia.org/wiki/Greater_London
Greater London, UK
London isn't in a county as such. It is part of Greater London which includes all 32 London Boroughs and the City of London.
Greater London.
WC2 is in the London Borough of Camden and would come under the county of Greater London.