I've just been testing this out. The World Map can go to the city map, but the city map does not go to the world map - a different one is loaded up each time, even when going from World to City and back to World.
Thanks for the message! I'm pretty (like ~90% :)) sure that World→City→World should work as expected (i.e. the original world map should be displayed). Maybe we've broken something, I'll try to find out.
