Only one "municipality" is listed in this category, Frettinga. It doesn't appear to be a real place at all. I believe this is a practical joke. If Frettinga is real, where is it exactly?
Topic on Category talk:Municipalities/Flow
This is, indeed, a demonstration of how the translate extension works rather than an attempt to seriously convey information (see Help:Extension:Translate/Page translation example). But everyone should know this wiki is supposed to document the software, not provide information about places, so I don't see the problem.
I found the article on wikipedia by clicking on Random article. It looks like a wikipedia article. I was just trying to help edit wikipedia. But it sounds like this is not actually wikipedia, but some other wiki I've never heard of. Can you set it up so that it doesn't link to wikipedia's random article button?
The actual random article button on Wikipedia can't link here. What I suspect happened is that you followed some other link to this website from Wikipedia, and then, thinking you were still on Wikipedia, clicked "Random page" here. There's nothing I can do about that.