I was coming back home and I entered, on the sat nav, an area of unexplored land, you know where dragons be. The arrow was there but no roads, rivers or anything, the screen was white with a moving arrow? It was like an old Victorian map where no explorers had been before, THIS AREA IS UNEXPLORED COUNTRY.

Is there any reason for this or was I just dreaming, and will I wake up again soon?

I hit some of that in the Lake District. I had to get out my phone and let Google Maps finish the job. Can't help with the reason, though. Satellite black spot?

Quite likely an area that is either newer than the version of the maps you have, or an area that the makers of the map data thought wasn't needed.  Our estate isn't on the maps that I have in my Superb (2016 maps, although in theory the estate should be there as we've lived here since new - 2014).  I've also seen some modern Mercedes show a petrol station where there is none (used to be, but trashed and built into a block of flats in '08).  

 

Or, you could have strayed onto a top secret military base of some description...are you sure that you haven't been probed?  

 

A

It did say Area 51 does that have any significance? This was actually an area of established countryside outside Stoke on Trent that has been untouched for eons so no reason for lack of mapping.. There was a Listening station at Cheadle , Staffs but that has been closed for at least 20 years perhaps more but that was some miles from where I am referrring. Fortunately I know my way home by now, otherwise I quite like the sat nav, but I am looking forward to the updated system in the newer Superb’s, although I might consider a Kodiaq next.