A sectioned-off part of the Serpentine Lake, this freshwater lido has lured locals for over 100 years – despite the goose detritus – because everyone is up for relaxing things to do in London once in a while. At its maximum, there are 100 metres of straight swimming; there are also deck chairs, a paddling pool, a sandpit, a slide and swings, and the Lido Cafe in the old pavilion. But the ‘serps’, members of the Serpentine Swimming Club, don’t need any such bait – they swim here all year round from 6.30-9.30am. If you arrive early, you’ll see that wetsuits would be laughed out of town whatever time of year – many of the wiry serps compete in the Peter Pan Christmas Day Race when the water temperature averages 4°C. Goose excrement pales into insignificance.