I have an idea for the back of the tower! It can be the main location of any event or holiday event! Think about it. All that room can be for snowball fights (christmas) pumpkin archery (holloween) and more!
But, you almost never see that area, so almost nobody will be going there.
In Overwatch, a banner pops up like this:
So maybe have something like that that says go to the back of the tower or something like that.