Europe's grandest canyon runs an improbable shade of turquoise, and paddling into it from Lac de Sainte-Croix is the classic move: hire a kayak or pedalo at the Pont du Galetas and slip beneath limestone walls 700 metres high, swimming from any gravel beach that takes your fancy. July water is warmest; September has the same colour and half the flotilla. Arrive by 9am in high summer — the hire queues are their own endurance sport.
Featured in Ten wild swimming and water adventures across Europe · Adventure