Swimming outside on Christmas day in London? As mad (and unappealing to many) as that might sound, it's an annual tradition. Every year since 1864, the hardy members of The Serpentine Swimming Club race at 9am on Christmas morning at the south bank of the lake at Hyde Park, close to the Serpentine Caf\u00e9.\u00a0The Peter Pan Cup is so named because the trophy was donated by novelist J.M. Barrie in 1904 when his play Peter Pan made its London theatre debut. You need to be a club member to take part but a race isn't a race without spectators, so if you're in town and fancy a walk you can watch from a safe (and dry) distance.\u00a0Wrap up warm, and marvel at their swimmy stamina.