cloud-cuckoo-land

from WordNet (r) 3.0 (2006)

cloud-cuckoo-land
    n 1: an imaginary place where you say people are when they seem
         optimistically out of touch with reality

from The Collaborative International Dictionary of English v.0.48

cloud-cuckoo-land \cloud-cuckoo-land\ n.
   an imaginary place where fantasy and illusion predominate; it
   is a place where you say people are when they seem
   optimistically out of touch with reality.
   [WordNet 1.5 +PJC]