Time Out says
Watch a bunch of hardy folk freeze their gonads off in this Christmas Day swimming race in Hyde Park.
Strictly a spectator event - unless you happen to be a regular, not to mention hardy, member of the Serpentine Swimming Club - the Peter Pan Cup race takes place each year on Christmas morning.
The organisers point out that unless you're accustomed to swimming in extremely cold water (temperatures of below 40F are the norm), an impromptu dip could be the last swim you ever take – so you can't join the club on the day and take part. Much better anyway to make watching the race the focus of a brisk walk across Hyde Park to work up an appetite for the excesses to come.
The name of the 100-yard race derives from 1904, when author and playwright Sir James Barrie presented the first 'Peter Pan' cup to the winner, marking a change in the tradition that had seen the winner receive a gold medal since the race's instigation in 1864. The race starts on the south side of the lake, close to the Lido Café. Find out more here.