Even in the most peaceful of regions, something happens."
one indefinite, unspecified region, the most peaceful one imaginable out of all regions
To express the idea of "something being the case even in the most extreme circumstances", in English you usually use the construction "the most + peaceful(singular) + of + regions(plural)".
Now I wonder how you idiomatically say this in Italian. Should both "terre" and "pacifiche" be in the plural? Or is it more common to use some other singular-plural combination?
Anche nelle terre più pacifiche, ...