If you're caught on the hop, your best bet is to head for a bus that is heading over the river. You can't beat that combination of classic red, murky water, and the skyline.
This regal runaround packs more into a day than most cities can offer in a week. Hit Westminster Abbey early to avoid the crowds, then cut through St. James's Park to catch the Changing of the Guard at 11:20 AM at Buckingham Palace. (If the Palace doors are open, enjoy a peek at royal life.) Take a quick detour to the Tudor delights of St. James's Palace, old haunt of Charles I, before a promenade down the Mall past the Regency glory of Carlton House Terrace and through Admiralty Arch to Trafalgar Square.
Get an early start and a hearty breakfast, as this selection of treasures will likely keep you on your feet all day.
After lunch, choose from the treasures of the National Gallery, the Who's Who of the National Portrait Gallery, or a brass rubbing in the crypt of St. Martin-in-the-Fields if the children's interest is flagging. This should leave time for a stately stroll down Whitehall -- past Downing Street, Horse Guards Parade, and Banqueting House -- to the Houses of Parliament, where you have the option of prebooking a tour, or trying to get in to see a debate.
Her Majesty's mounted guardsmen make a great photo op -- you may even see Prince Harry, who joined the Regiment of the Blues and Royals, responsible for his grandmother's personal protection, after completing officer training at Sandhurst.
If you have any time or energy left, stroll through Green and Hyde Parks to Kensington Palace, childhood home of Queen Victoria, and (for little aspiring princesses everywhere) the Royal Dress Collection.
London has one of the finest collections of museums in the world, and certainly no other comparable city offers so much for free. Many resemble state-of-the-art, hands-on playgrounds; others take a more classical approach. One of the latter is the British Museum in Bloomsbury, an Aladdin's cave of artifacts from across the world. This is ideal for either a half- or full-day browse. If you want to combine your day with other visits, pop into the nearby museum of architect Sir John Soane, the Theatre Museum, or the newly refurbished London Transport Museum.
The excellent restaurant in the British Museum's Great Court looks down on its library, where Karl Marx would shift uncomfortably, greatly afflicted by boils, as he researched Das Kapital.
Alternatively, South Kensington's "Museum Mile" on Cromwell Road houses a triple-whammy, any one of which would make for a substantial half-day's worth of diversion: the Victoria & Albert Museum, the Natural History Museum, and the Science Museum.
It's not hard to shop 'til you drop in London's West End. Start with the upscale on New Bond Street in order to save your afternoon frazzled look for nearby Oxford Street. Home to (take a deep breath here) Cerruti, Chanel, Cartier, De Beers, Dolce & Gabanna, Armani, Jimmy Choo, Versace, Swarovski, Bulgari, Tiffany, Prada, and Gucci, it's an awesome sweep of expense and elegance.
Men should not pass up a chance to browse the shirts on show at nearby Savile Row, famed for its high-quality tailoring, and accessories on Jermyn Street.
Oxford Street encompasses four Tube stations and is unbeatable for mass-market shopping. Run the gauntlet of high-street designers, cheap odds and ends, department stores, and ferocious pedestrians: it's seriously busy, but you're pretty much guaranteed a buy.
A more sedate but utterly fashionable experience can be found in Knightsbridge, wandering between Harvey Nichols and Harrods department stores. Take a south down Sloane Street to Sloane Square and head out along King's Road, home to boutiques galore and once capital of London's swinging sixties.
To catch a glimpse of how to design your home to match your new couture clothes, visit the Conran Shop at 81 Fulham Road, parallel to the Kings' Road.
To dip into the ever-expanding world of urban chic, try an afternoon in the Portobello street market in Notting Hill, where you can pick up remnants of various bygone ages: glassware, furniture, art and clothes, from boiler suits to Thai silk dresses. Portobello has wised up to tourist prices in recent years, so a trip out to Spitalfields (covered) market on a Sunday is worth considering, especially for a sample of the East End. Finally, for the younger crowd, Camden market has grunge and clubbing wear in spades.
The easiest village to reach is Hampstead, 20 minutes from the city center by Tube, but a world away in character. It's home to a thriving arts scene, a history of left-wing poets and writers (including John Keats), some of the most gorgeous Georgian houses in London (hence the occasional jibe of "Champagne Socialism"), and a great range of smart shops, bistros, and French delicatessens.
If you're in Hampstead, don't miss the chance to get out onto the Heath, moodier and wilder than many of London's other open spaces.
To the west, leave the slightly suburban center of Richmond behind to get down to the riverside, or head for the vast expanse of the park next door, which breaks all remaining links with city life.
The fantastic views bestowed on Greenwich, to the south of the Thames, ensure you never forget how close the city is -- and yet this village's nautical past creates an almost seaside feel. The National Maritime Museum and its collection of fine buildings, as well as two very good markets, make it a worthwhile day trip.
To the east, Bethnal Green is a village in the midst of an urban renaissance. Visit the flower market of Columbia Road, the Children's Museum, and the paths along the canal.
To appreciate fully how tribal London's villagers can be, try asking which part of the city they come from or live in. The responses you'll get -- "Haggerston," "Tufnell Park," "Turnham Green," "Camberwell," "Battersea" -- indicate a dizzying array of identities, often consisting of a few neighboring streets.
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