The Prince's Castle is the place where the Prince takes Snow White to after awakening her from her death-like sleep and where they both lived happily ever after.
The castle appears to have thick tall walls that also serve as the base, 3 predominant sections of towers each connected by archways. Most of the spires are pink in color and there are 17 seen. The "castle in the air" if you will, seems to face west through the entrance is undefined (as it is for a lot of other Disney castles.)
Some fans believe that the ending of Snow White and the Seven Dwarfs shows the Prince and Snow in Heaven when the castle is shown, because of it looking like the castle is in the clouds.