What does an inconsistently recurring dream-setting indicate?

As in on the rare occasion I actually remember a dream, it seems that I was moving through a very familiar dream-space.

To analogize, say you sometimes have dreams that take place in your bedroom. But in each bedroom dream, you’re doing something different, or there are different people sharing the dream-space with you, or you feel different, etc. The only common thread tying these dreams together is the location.

I don’t really talk to other people about dreams, but I think on the whole this is a pretty normal occurrence. What makes me curious is that in my case, the location is someplace I’ve never been to. It’s fictitious.

So it’s an environment that shows up every now and then, I mean. It is a space that doesn’t exist in reality but only in my dreams, and as far as I can tell it isn’t clearly derived from any actual location I’ve visited. On the whole it’s mundane: a curved road or path leads from a few low-slung steps down to the edge of a high hill that overlooks various flora.

The dream itself is infrequent and not recurring, and what I do in the familiar dream-space apparently differs every time. But it’s hard to say exactly where the differences are, because I rarely (remember what I) dream and do not keep a dream journal or anything, so I can’t compare.

It also makes me wonder whether one can experience deja vu within a dream, because I can’t even be certain I’ve dreamed of this space before. It could be a false feeling of recognition of familiarity that convinces me I’ve been there before while dreaming.

I guess my questions then are
1) What is the significance of a recurring setting for one’s dreams, but a setting which is fictive and should thus (presumably) have little to no inherited meaning from the real/waking world?
2) What is the significance of its fictivity?
3) What is the significance of its inconsistency?
4) Is there such a thing as a deja vu that exists only in dreams?

What do you think?