"Imaginary places" is actually an official term library catalogs use to describe books in which the Imaginary Place is central. Click the link below to browse related subjects.
You can even look up the name of some specific author-created imaginary places:
Some other places are easier to find in a keyword search:
Believe it or not, books are also classified with these terms:
Myth and folklore might also give you some ideas:
Chronologies may be another source to stimulate your thinking:
To find books and other materials on past authors who have created imagined worlds or explored actual places in their poetry and fiction, try these keyword searches in the Classic Catalog:
Actual Places or based upon them