London is the capital of England and the United Kingdom is a 21st-century city with history extended back to Roman times. London is one of the major global cities in the research and development, tourism and transportation, professional services, arts, commerce, education, entertainment, fashion, finance, healthcare, media. It has the fifth or sixth largest metropolitan area GDP and it is the world's largest financial centre. London is often considered as a world cultural capital. It is the world's most-visited city as a study by international arrivals and has the world's largest city airport system measured by passenger traffic. It is the world's leading investment destination, hosting many international retailers and ultra-high-net-worth individuals than any other city. London's universities form the largest attentiveness of higher education institutes in Europe. In 2012, London became the first city to have organized the modern Summer Olympic Games three times.

London contains four World Heritage Sites: the Tower of London; Kew Gardens; the site comprising the Palace of Westminster, Westminster Abbey, and St Margaret's Church; and the historic settlement of Greenwich (in which the Royal Observatory, Greenwich defines the Prime Meridian, 0° longitude, and GMT). Other landmarks include Buckingham Palace, the London Eye, Piccadilly Circus, St Paul's Cathedral, Tower Bridge, Trafalgar Square and The Shard. London is home to many museums, galleries, libraries, sporting events and other cultural institutions, including the British Museum, National Gallery, Natural History Museum, Tate Modern, British Library and West End theatres. The London Underground is the oldest underground railway network in the world. Over the Thames River, the London Eye observation wheel provides far reaching views of the South Bank cultural complex and the entire city.