Bielefeld, Germany, a modest city of 338,000 people, is in every way typical of a well-off German town, with an opera house, a castle and a tidy historic district.

In fact, the city is so impossibly bland, according to a well-worn gag, it can’t possibly be real; all evidence to the contrary must be part of a giant conspiracy.

“Have you ever been to Bielefeld?” the joke goes. “Can you name one thing about Bielefeld?” The answer, of course, is no.

Even Angela Merkel, the former chancellor, piled on, saying in 2012 that she had given a speech in the city, “if it even exists.”

Bielefeld has gamely played along, even working the teasing into its marketing. But it clearly irks local residents.

“Everyone laughs at us, because of this joke,” said Timo Teichler, the morning host on Radio Bielefeld. “Yeah, ‘Bielefeld doesn’t exist.’ I hate that joke.”