“NAKED, we are equal,” proclaims Ida Karkiainen. The Swedish MP is addressing a packed hall at the 17th International Sauna Congress in Tornio, Finland. She draws a round of applause from the crowd, a mix of sauna entrepreneurs and enthusiasts from Europe and Japan, along with a few North Americans. It is important, Ms Karkiainen continues, that both sexes sit nude in the sauna together. After all, political and business deals are often made in the swirling steam, and one would not want such an important venue of power to exclude men.

It is hard to imagine such a speech being made by a politician anywhere outside Europe. Beginning in the late 19th century, ideas about freedom, equality, health, sexuality and public space came together to create a distinctly European enthusiasm for going unclothed. In Scandinavia the focus was the sauna. In Mediterranean countries it was the beach. In Germany it was everywhere: the country’s Freikörperkultur (“free body culture”, or FKK) encourages stripping off while gardening, playing sports or taking lunch breaks in the park.

Yet Europe’s taste for bare skin is in retreat. Nudist beaches and resorts, topless sunbathing and nude unisex saunas are declining. Football teams report that players are unwilling to remove their underwear to shower after matches. In recent years, commentators across the continent have remarked on a new prudishness.

The retreat of nudity has unpredictable political overtones. During Germany’s election campaign in 2017, Gregor Gysi, the leader of the Left party, lamented the conservative turn represented by the decline of FKK, which had been strongest in the former East Germany. In the Netherlands, the issue is more often invoked on the right. In 2016 Mark Rutte, the centre-right prime minister, worried about a future in which nude beaches have vanished because the country has “surrendered to the wishes of a cultural minority”—by which he meant Muslims.

But while immigration plays a role in Europe’s increasing modesty, other factors are more important. The rise of social media has made young people more body-conscious, reluctant to display anything less than perfect abs. Smartphones with cameras make risqué undress riskier. The #MeToo movement has forced a reassessment of even fully clothed interactions between the sexes, let alone naked ones. And the increasing ubiquity of online pornography is making it difficult to de-sexualise the naked body, a prerequisite for nudist beaches and unisex saunas.

Today, nudists complain, it is more difficult to separate nakedness from sex. French nudists say their movement’s younger members are overwhelmingly men; women are leery of being leered at. “Parts of Cap d’Agde have been completely sexualised,” says Wim Fisscher, owner of Adam and Eve, the last nude beach restaurant in the Dutch town of Zandvoort. He has had to turn away Dutch sadomasochists who turned up with leash and collar. Toplessness on European beaches is dwindling. In 1984 a survey found that 43% of French women under 50 sunbathed bare-breasted. By 2017 that had fallen to 22%, and arguments over beachwear centred not on whether bottoms-only suits covered too little but on whether the long-sleeved “burkinis” worn by some Muslim women covered too much.“On the one hand young people nowadays watch the craziest sorts of porn, and on the other they find it harder to take their own clothes off,” observes Mr Fisscher. In the late 1980s there were seven nude restaurants in Zandvoort. He estimates that the average age of his patrons has risen to about 50.

If any space is more embarrassing for non-European tourists than a French nude beach, it is a German or Dutch sauna. They are unisex and naked by default. All bodies, thin, fat, young or old, are treated non-judgmentally. The one thing that will earn a disapproving stare is wearing clothing, because such modesty implies an inappropriate level of sexual consciousness.

The latest German innovation is the aufguss (“infusion”) sauna, in which nude audiences enjoy Las Vegas-style performances by muscular, towel-swirling emcees who infuse the steam with herbal aromas. The paradigmatic Dutch sauna might be Zuiver (“Pure”), a spa complex outside Amsterdam whose name subliminally links nakedness with the country’s nothing-to-hide Calvinist morality.

Sweating, the details

Yet in 2011 Zuiver introduced swimwear days, currently three per week. Most Dutch saunas now have clothing-optional hours. Fear of unwanted photos is not a problem: mobile phones must be handed in at the door. But sauna owners say that with mores changing, they need to appeal to potential clients who are more bashful, whether because they are young or from conservative immigrant backgrounds.

There are pockets of Europe where social nudity is getting a second wind. Jesce Walz, an architecture student researching saunas, notes a wave of hip new public ones in Finland, where they were once mainly found in private homes. In Sweden, more mixed-sex saunas are opening. French nudists say urban get-togethers such as nude bowling nights are packed, though overwhelmingly with men.

But the vision of nakedness as a demonstration of freedom and equality seems to be faring less well. Nudity has been central to European culture since the Greeks first sculpted Hermes. That will not change. What may be vanishing, though, is a particular 20th-century European dream, for which all one needs is a patch of Mediterranean coast or a Scandinavian forest and the willingness to strip off.