With Bats and Supes apparently set to battle it out later in the year all across America, news footage now shows the production of the above set in Deming, New Mexico. As an Australian, the place really couldn't be further away from me, and yet I have a few guesses as to what it could be, as I'm sure you all do.
The main one, of course? Themyscria, home to [Wonder Woman](movie:45787) and the Amazons. The very Greek architecture, what looks to be a palm tree atop one of the buildings, and the look of the building in the back right very much like a Greek Parthenon all seem to be quite indicative we're seeing Wonder Woman's home being built ready to film a few scenes. Which I'm happy about, as, even though she's probably just a supporting character, Wonder Woman deserves this to be acknowledged, and I think it will be done well from the looks of it.
Normally,Themyscria is an island surrounded by water (bit redundant) in the Bermuda Triangle, and is indeed often floating, but other variations appear. What's unlikely is that they'll leave it in the middle of a desert, as I'm sure you all think, and so CGI of the outside seems highly likely. As it happens, water happens to be easy to generate on a computer. Whatever route they take, the architecture seems right, and the recent confirmation of Diana's Demigod backstory made me very happy. If they go the route of big ships and statues worthy of Braavos, CGI seems even more likely.
Below are some more photos and the news report featuring the set footage. It's not guaranteed to be Themyscria, mind- it could well be another place, ranging from Nanda Parbat to Egypt. Themyscria just seems most likely and consistent with the story the film is telling.
Info first drawn from Comicbook.com.