3. Fancy hotels
Like the famous department stores, London's high-end hotels step it up a notch at Christmas. The Ritz has a 7m-tall Christmas tree with 10,000 decorations and 6500 lights; Claridges has carol singing on Christmas morning; The Lanesborogh serves a festive-inspired afternoon tea, and last year The Savoy had a 5m helter-skelter in its front hall and a giant snow globe in its foyer.
4. Bright lights
If you can ignore the crowds, London is a magical place to walk around in November through to early January, thanks to the myriad lights and decorations. Oxford St's Christmas lights get switched on by a celebrity — previous stars have included Enrique Iglesias, Kylie Minogue, Robbie Williams, the Spice Girls and Jim Carrey — and the ceremony usually attracts one million people. You'll also find impressive displays in Covent Garden, Regent, Carnaby and Bond Sts, and The Shard puts on an annual light show.
5. Christmas markets
Long a tradition in European cities like Budapest, Prague and Vienna, you'll now also find great Christmas markets in London. Hyde Park is home to one of the biggest — Winter Wonderland, which has more than 200 wooden cabins packed with gifts, as well as the UK's biggest outdoor ice rink, a giant observation wheel and regular Christmas shows.
6. Pantomimes
You should definitely go to a British pantomime once in your life. ("Oh no, you shouldn't." "Oh yes, you should.") Although completely cheesy, kitsch and camp, they're still a lot of fun. They're also a chance to see on stage former big-name celebrities who are trying to stop their slow slide into obscurity. David Hasselhoff, Pamela Anderson and Priscilla Presley have appeared in panto and, would you believe, Sir Ian McKellen — Gandalf himself — once played Widow Twanky in an Old Vic performance of Aladdin.