London's location is the United Kingdom.
The British Library is the national library of the United Kingdom and the second largest library in the world by number of items catalogued . City of London . Both of these terms are also often used as metonyms for the United Kingdom 's trading and financial services industries , which continue a notable history of being largely based in the City . Greenwich Mean Time . It is a term commonly used in the United Kingdom and countries of the Commonwealth , including Australia , New Zealand , South Africa , India , Pakistan and Malaysia ; and in many other countries of the eastern hemisphere . London . London 's ancient core , the City of London , largely retains its 1.12 sqmi medieval boundaries .