London's contrasts and cacophonies both infuriate and seduce.
London - the grand resonance of its very name suggests history and might. Its opportunities for entertainment by day and night go on and on and on. It's a city that exhilarates and intimidates, stimulates and irritates in equal measure, a grubby Monopoly board studded with stellar sights.
'When a man is tired of London, he is tired of life; for there is in London all that life can afford.' - Samuel Johnson
It's a cosmopolitan mix of Third and First Worlds, chauffeurs and beggars, the stubbornly traditional and the proudly avant-garde. But somehow - between 'er Majesty and Pete Doherty, Bow Bells and Big Ben, the Tate Modern and the 2012 Olympics - it all hangs together.
The security threat in the United Kingdom remains at a significant level following recent terrorist incidents in London and Glasgow. Travellers should exercise caution, monitor the media for any developments in the situation and expect delays at airports due to increased security measures.
Restrictions on airline cabin luggage are in place throughout the UK. For details check the UK Department for Transport website.
The main geographical feature of the city is the River Thames, which meanders through central London, dividing it into northern and southern halves. The central area and the greatest number of important sights, theatres and restaurants are within the Underground's Circle Line on the north bank of the river. In the past decade, however, the south bank of the river has been transformed into one of London's must-see district, with attractions such as Borough Market, the London Eye, Shakespeare's Globe theatre and the Tate Modern art gallery. The tourist-ridden West End includes Soho, Trafalgar Square, Piccadilly Circus, Leicester Square and Regent St. The East End, so beloved of Ealing comedies, lies east of the Circle Line; it used to be the exclusive preserve of the Cockney but is now a cultural melting pot. There are interesting inner-city suburbs in North London, including Islington and Camden Town, with leafy Hampstead further north. Further south, London includes a mix of poor, dirty, graffiti-ridden suburbs, and increasingly gentrifying areas like Clapham and, to an extent Brixton.