With a population of just under eight million, London is Europe's largest city, spreading across an area of more than 620 square miles from its core on the River Thames. Ethnically it's also Europe's most diverse metropolis: around two hundred languages are spoken within its confines, and more than thirty percent of the population is made up of first, second- and third-generation immigrants. Despite Scottish, Welsh and Northern Irish devolution, London still dominates the national horizon, too: this is where the country's news and money are made, it's where the central government resides and, as far as its inhabitants are concerned, provincial life begins beyond the circuit of the city's orbital motorway. Londoners' sense of superiority causes enormous resentment in the regions, yet it's undeniable that the capital has a unique aura of excitement and success - in most walks of British life, if you want to get on you've got to do it in London.

For the visitor, too, London is a thrilling place - and since the beginning of the new millennium, the city has also been overtaken by an exceptionally buoyant mood. Thanks to the lottery and millennium-oriented funding frenzy of the last few years, virtually every one of London's world-class museums, galleries and institutions has been reinvented, from the Royal Opera House to the British Museum. With the completion of the Tate Modern and the London Eye, the city can now boast the world's largest modern art gallery and Ferris wheel; there's also a new tube extension and the first new bridge to cross the Thames for over a hundred years. And after sixteen years of being the only major city in the world not to have its own governing body, London finally has its own elected mayor and assembly.

In the meantime, London's traditional sights - Big Ben, Westminster Abbey, Buckingham Palace, St Paul's Cathedral and the Tower of London - continue to draw in millions of tourists every year. Monuments from the capital's more glorious past are everywhere to be seen, from medieval banqueting halls and the great churches of Sir Christopher Wren to the eclectic Victorian architecture of the triumphalist British Empire. There is also much enjoyment to be had from the city's quiet Georgian squares, the narrow alleyways of the City of London, the riverside walks, and the quirks of what is still identifiably a collection of villages. And even London's traffic pollution - one of its worst problems - is offset by surprisingly large expanses of greenery: Hyde Park, Green Park and St James's Park are all within a few minutes' walk of the West End, while, further afield, you can enjoy the more expansive parklands of Hampstead Heath and Richmond Park.

You could spend days just shopping in London, too, hobnobbing with the upper classes in Harrods, or sampling the offbeat weekend markets of Portobello Road and Camden. The music, clubbing and gay/lesbian scenes are second to none, and mainstream arts are no less exciting, with regular opportunities to catch brilliant theatre companies, dance troupes, exhibitions and opera. Restaurants, these days, are an attraction, too. London has caught up with its European rivals, and offers a range from three-star Michelin establishments to low-cost, high-quality Indian curry houses. Meanwhile, the city's pubs have heaps of atmosphere, especially away from the centre - and an exploration of the farther-flung communities is essential to get the complete picture of this dynamic metropolis.

Stretching for more than thirty miles at its broadest point, London is by far the largest city in Europe. The majority of its sights are situated to the north of the River Thames, which loops through the city from west to east. However, there is no single predominant focus of interest, for London has grown not through centralized planning but by a process of agglomeration - villages and urban developments that once surrounded the core are now lost within the amorphous mass of Greater London.

One of the few areas that you can easily explore on foot is Westminster and Whitehall , the city's royal, political and ecclesiastical power base, where you'll find the National Gallery and a host of other London landmarks, from Buckingham Palace to Westminster Abbey and Big Ben. The grand streets and squares of St James's , Mayfair and Marylebone , to the north of Westminster, have been the playground of the rich since the Restoration, and now contain the city's busiest shopping zones.

East of Piccadilly Circus, Soho and Covent Garden are also easy to walk around and form the heart of the West End entertainment district, containing the largest concentration of theatres, cinemas, clubs, flashy shops, cafés and restaurants. To the north lies the university quarter of Bloomsbury , home to the ever-popular British Museum, and the secluded quadrangles of Holborn's Inns of Court, London's legal heartland.

The City - the City of London, to give it its full title - is at one and the same time the most ancient and the most modern part of London. Settled since Roman times, it is now one of the world's great financial centres, yet retains its share of historic sights, notably the Tower of London and a fine cache of Wren churches that includes St Paul's Cathedral. Despite creeping trendification, the East End , to the east of the City, is not conventional tourist territory, but to ignore it entirely is to miss out a crucial element of contemporary London. Docklands is the converse of the down-at-heel East End, with the Canary Wharf tower, the country's tallest building, epitomizing the pretensions of the Thatcherite dream.

Lambeth and Southwark comprise the small slice of central London that lies south of the Thames. The South Bank Centre, London's little-loved concrete culture bunker, is enjoying a new lease of life thanks to its proximity to the new Tate Gallery of Modern Art in Bankside, which is linked to the City by a new pedestrian bridge.

The largest segment of greenery in central London is Hyde Park, which separates wealthy Kensington and Chelsea from the city centre. The museums of South Kensington - the Victoria & Albert Museum, the Science Museum and the Natural History Museum - are a must; and if you have shopping on your agenda, you'll want to check out the hive of plush stores in the vicinity of Harrods.

The capital's most hectic weekend market takes place around Camden Lock in North London . Further out, in the literary suburbs of Hampstead and Highgate, there are unbeatable views across the city from half-wild Hampstead Heath, the favourite parkland of thousands of Londoners. The glory of South London is Greenwich, with its nautical associations, royal park and observatory (not to mention its Dome). Finally, there are plenty of rewarding day-trips along the Thames from Chiswick to Windsor , most notably Hampton Court Palace and Windsor Castle.