Everyone seems to like Marleybone, cause it's the only world where it is night time. What if Skull Island could be at night? Or ... Mooshu at night time! Maybe after El Dorado, nighttime could be a feature introduced for worlds.
Or maybe you can also choose how the sky will look like? Imagine Skull Island with an avernus sky! Waponi Wu would be a cool place to visit at that time! I am having De ja vu that I already posted this but I can't remember.