Dark Knight Rises Set Photo. Is It The Lazerus Pit?

This pic has the hit the net of a set photo from the India shoot for The Dark Knight Rises.  No one really knows what it is but the general consensus seems to be that it's the Lazerus Pit.  No one knows really but the people working on the film.  Christopher Nolan says this is his final Bat film so perhaps he's wrapping the trilogy up by connecting it with Ra's ah Ghul from Batman Begins.  We will all find out next summer!