The Castles at the 5 magic kingdom parks are all situated to have the castle face due south....i believe.....
by that description.....the back side of contemporary is due East (which it is).....and the back side of Grand Floridian is due west (which it almost is....more like northwest)
so the sun sets over the contemp and sets over the grand....almost exactly....assuming your there on the first day of spring or fall