Fed up with repeated incursions by German nacktwanderen (naked hikers), in 2009 a northern Swiss canton passed a law making such hiking illegal. See "New Swiss Law Aims to Halt Invasion of Naked Germans," Lowering the Bar (Apr. 26, 2009). A man convicted of breaking this law a few months later ultimately appealed the case to the Swiss Supreme Court, which ruled against him last week.
Is it too late to warn you about the mildly NSFW photo appearing at that second link, which appears to show one of the nacktwanderen proudly greeting the sunrise? It is? Sorry about that. At least the picture was taken from the direction of the sunset.
The hiker who challenged the law was actually acquitted by the trial judge, who appears to have found the local law preempted by the Swiss Penal Code, which the judge ruled regulates all crimes involving "sexual integrity," whatever that is. But the court of appeal disagreed and ordered the man to pay the fine. He appealed to the high court, but lost. "It is not arbitrary," the court held, "to consider naked hiking in public a gross breach of decency and convention." The activity is still legal in the rest of the country, it appears, but please don't take that as legal advice. You nacktwander at your own risk.
Many of the reports use the word "naked" instead of "nude"; the two are pretty close synonyms but "naked" tends to imply resulting discomfort or embarrassment, and obviously neither of those were involved here. So I went with "nude hiking" for the headline. A French report on this story refers to the guy as a "nudist rambler," but I'm not sure that has the same connotation in English. "The Nude Ramblers" would be a pretty good name for a band, though.