It's a German city dating back to the 9th Century, with 340,000 residents, a university, a medieval fort... but does it really exist?

Bielefeld is now offering a €1m (£914,000) prize to anyone in Germany who can prove the city's non-existence.
...
Achim Held, an IT student, was at a party in Kiel, a northern port city, when a guest turned up from Bielefeld - but Achim was quite unaware of the city's existence. Other party guests were also baffled by Bielefeld, German broadcaster ARD reports.

Soon after that, Achim could not resist posting the message "Bielefeld? There's no such thing" after spotting that a motorway sign for Bielefeld had been crossed out because of roadworks.

https://www.bbc.co.uk/news/world-europe-49432677