never-never land

[After Never-Never Land, fictional setting used in the play Peter Pan by J.M. Barrie.]

A fantasy land, an imaginary place, as in I don't know what's gotten into Marge--she's way off in never-never land. This expression gained currency when James Barrie used it in Peter Pan (1904) for the place where Peter and the Lost Boys live. However, in the second half of the 1800s Australians already were using it for vast unsettled areas of their continent ( the outback), and there the term became popular through Mrs. Aeneas Gunn's We of the Never Never (1908). In Australia it still refers to northwest Queensland or northern Australia in general. Elsewhere it simply signifies a fantasy or daydream.

The noun has one meaning:

Meaning #1: a pleasing country existing only in dreams or imagination
  Synonyms: dreamland, dreamworld