how about
- maybe visiting a movie set, or putting up a play?
-or a concert/music festival
-or greek/roman/japanese myth
-or Angkor Vat,
-or a superheroes theme, with heroes vs villains (like dreams vs nightmares) (i think someone mentioned it already)
some of the ideas from previous threads that i loved:
- oooh the mystery in a noir vintage setting sounds cool, (need not be a murder mystery, it could be a missing item or person to sleuth down

)
- waterpark
- museum
- masquerade ball
-school of magic hehe wink wink a generic school of magic you know?
-cafe/restaurants or like summer jobs theme lol where we do a car wash, bake sale etc

-helping a friend run a pet store or any other kind of store/business