i've got three places in mind:
eastern central rockies
northeast bosnia
southern siberia
just gotta keep stackin and one of them is gonna stand out for some reason
we have english on one, i already know a decent amount of serbo croatian on the other, and last one knowing serbo-croatian helps a lot with russiand and plus i have some bulgarian
these are my preferred locations becaues they are high altitude and far from the coasts (the central mediterranean is a shallow basin relatively speaking)