Synonyms to castle in Spain

castle in the air, Xanadu, airy nothing, autism, bubble, chimera, daydream, deception, deluded belief, delusion, dereism, dream, dream vision, dreamland, dreamworld, false belief, ignis fatuus, illusion, misbelief, misconception, pipe dream, self-deceit, self-deception, self-delusion, trick, trip, vapor, wrong impression