When it comes to swimming in the capital, we're spoilt for choice. Lane swimming doesn't have to mean drab, windowless, verruca-inducing sites of school sports lessons, and open water swimming doesn't always involve slimy encounters with fish and suspicious-looking algae: this highly opinionated guide includes only the very best places to derobe, take the plunge and unwind. Whether you want to clock up lengths, doggy paddle laps or relax with a cocktail and a view across London in Western Europe's highest pool, there's plenty here to dip your toe - or dive headfirst - into.