Isabella and Ferdinand, for instance, had these dreams about future success (7,2,5)
I believe the answer is:
castles in spain
I believe this clue is a double definition.
'isabella and ferdinand for instance had these' is the first definition.
(Isabella and Ferdinand were Spanish monarchs)
'dreams about future success' is the second definition.
(term for daydreams or unrealistic ideas)
(Other definitions for castles in spain that I've seen before include "pipe dreams" , "Wild dreams" , "Continental chessmen?" , "Unrealistic plans" , "Daydreams" .)