The “free-body culture”, or FKK, in Germany is waning due to the use of smartphones and modern perceptions of beauty, enthusiasts claim

For nearly a century bare bottoms have been as inescapable a fixture of the German summer as barbecues and beer.

The country gave the world its first naturist association and today there are dozens of clubs dedicated to Freikörperkultur — “free-body culture”, or FKK — that offer naked yoga, naked hillwalking and naked badminton.

Yet nudist societies say the pastime is beginning to wane in the age of smartphones, red-faced foreigners and puritanical modern standards of beauty.

Membership of the national FKK organisation is falling by 2 per cent a year. Bathhouses that once vigorously imposed nudity on their customers now allow or even oblige them to cover up. Swimsuits are increasingly de rigueur on beaches. Surveys even suggest that Germany has been overtaken by