A small town in Überwald which has a proud tradition of training Überwaldean clowns and sending out its people into the world as ambassadors for the renowned Überwaldean sense of humour. It is also a place famed in history for its tradition of sloshi, the Clowns' martial art, no doubt to be used only in self defence, or whenever anyone makes a statement like "Hang on, Überwaldeans don't have a sense of humaaaaargh!"
Müning being a homonym for the verb "Mooning", i.e. the humorous showing of one's rear to others, generally in public and always inappropriately.
Of course there's also the Roundworld city of Munich...
A late sixties' Hammer horror film was called Vampire Circus, and used the idea of a travelling circus working the dark hinterland of Central and Eastern Europe, which carried among its number several vampire performers, who could perform, feed, then move on before they were noticed. Given that it may have used the doubly horrifying concept of a vampire clown, this makes the idea of Müning being the centre of Überwaldean clowning doubly more plausible and infinitely more scary. After all, what better way for a travelling circus or company of clowns to defend itself against Überwaldean terrors of the night, than to have some in the cast?