It's September 1945 and your students will take what they've learned about the course of WWII, geography, the emerging chilliness between the US and USSR to create their own post-war settlement, bigger than Yalta or Potsdam.
In just this one activity, students get to create, research, synthesize, write, speak, compromise, use geography, consider both cause and effect and they get to be loud and animated while doing it. Students often say this is their favorite activity of the year.
I've used this as a final exam for WWII, a unit test, a review before beginning a new semester starting with the Cold War. It's versatile.