This dual pyramid extends down (from street level) into the Louvre's underground promenade to meet a smaller up-thrust pyramid directly below it.
In The DaVinci Code, Dan Brown suggests that the last resting place of Mary Magdalene is beneath this unusual dual pyramid located at the west end of the Louvre's underground promenade:
The holy grail 'neath ancient Roslin waits.
The 'blade' is a pyramid pointed up; the 'chalice' is a pyramid pointed down. The Star of David is a blade and chalice overlain upon each other.
In the movie, we see Robert Langdon (Tom Hanks) standing above this at the street level, but one would have to climb over a very imposing hedge whose purpose is clearly to prevent people walking across its glass surface.