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 therefore the historic settlement of Greenwich (in which the Royal Observatory, Greenwich defines the prime meridian, 0° longitude, and GMT). different landmarks include Buckingham Palace, the London Eye, Piccadilly Circus, St Paul's Cathedral, Tower Bridge, Trafalgar square and therefore the shard. London is home to numerous museums, galleries, libraries, sporting events and different cultural establishments, 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.

London is a leading global city in the arts, commerce, education, entertainment, fashion, finance, healthcare, media, professional services, research and development, tourism and transportation. it's the world's largest financial Centre and has the fifth or sixth largest metropolitan space GDP in the world. London is usually regarded as a world cultural capital. it's the world's most-visited city as measured by international arrivals and has the world's largest city airport system measured by passenger traffic. it's the world's leading investment destination, hosting more international retailers and ultra-high-net-worth people than any other city. London's universities form the largest concentration of higher education institutes in Europe. In 2012, London became the first city to possess hosted the modern Summer Olympic Games thrice.