In Dragon Warrior 4..I'm pretty sure that Dragon's Castle is in the clouds..In fact, I think it's shown like that on the title screen..(It's the final area of the game where you're taken after you defeat the last boss.)

And, I don't know if you can count this or not..but at the end of Kirby's Dream Land, Kirby turns into a blimp and carries off King DeDeDe's Castle. Then, he flies away with it, and after he lets go of it, it gets suspended in midair by the four Dream Land Stars.
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