Originally Posted by alexander
No, the word tani is always pronounced tani. When you use its kanji as part of the word muumindani the reading is softened because it's preceded by an n. If you make it two words you have to put a particle in between but get the normal reading: muumin no tani.
EDIT don't take this as a general rule, though, especially in names. 新谷 for instance is shintani.
It's the same for 川 kawa and 小川 ogawa.
hmm though in this case you mentioned the wiki name with the 'no' particle in between... so then, based on what you just said, wouldnt that be two words = muumin no tani?