In what has inexplicably become a self-flagellatory festive tradition, hundreds of Londoners will be diving into cold ponds of dirty water on Christmas morning. The most famous event is in Hyde Park where members of the Serpentine Swimming Club race for the Peter Pan Cup, donated by JM Barrie in 1904. It probably won't be too much of a disappointment to discover that this is a members-only event, but spectators (and TV crews) are welcome - the lunacy commences at 8am. The Lifebuoys Club on Hampstead Heath organises a 50-yard race for the foolhardy at 10.30am at the men's pool near Merton Lane. The event is free, open to all-comers and, although women are not officially allowed, anyone keen enough to turn up should be admitted. Finally, the open-air Hampton Pool (info: 0181-979 9933) offers a less masochistic alternative. Its waters are clean, heated to 82 degrees and the pool is open between 8am and midday with a smoked salmon and bucks fizz breakfast on offer in the cafe upstairs.