Upside Down

I would be shocked if you have seen UPSIDE DOWN (2012), a film staring Kirsten Dunst and Jim Sturgess, and I am not recommending it, but it's worth knowing that this ball room set exists:

The concept of the film is that there are two planets positioned right next to each other.  The gravity of a planet only works on the matter that originates from that planet, and vice versa (FYI: this is not how physics works).  This means that if you are from World A and you go to a dance club on World B, you will be dancing on the ceiling (because your planet is sticking you up there), while the people from World B are dancing around on the ground like normal.  

Or if you are on World B and you order a World A Cocktail, you have to drink it upside down or else the liquid will try to fly up and get back to World A where it comes from.

And if you are running an interworld dance club, you better make sure people can tango on the floor and the ceiling.