Time for another proposal: map a place where different cultures, or different fantasy races or different sci fi species or different multicultural you choose what, live or can be found and try to achieve a common good (in which they are succeeding or not).
From a fantasy kingdom which is inhabited by elves and orcs living together to a Star trek like United Federation, filled with alien cultures; from the Seat of an International interreligious organization, to a multicultural city or nation: I think there are plenty of possibilities, ranging from fantasy, scifi and uchronic thematics, to more actual and realistic ones.