Is it possible to have a dream about a place you didn't know existed at first, but is real?

This answer is more complicated than you think. The part about it being real is a close facsimile of an actual place. An example would be of creatures in nightmares seem real but most definitely do not exist. The components of the creature are through pieces of experiences from movies, magazines and emotions through out your life. The complexity of the brain embles these factors to formulate a complex imagery for some purpose not always fully understood. There is no arial projection or psychic photo reconasense. Just the complexity of the brain making the most of what it has.