Menel (Q."Heaven; Firmament; Sky"), also called Elenarda (Q."Stellar-Kingdom") or Ilmen (Q. "Place of Light") was the Region of Stars, it included Sky and all of the heavens and lay above Arda. Firmament also referred to the most exalted region of the Timeless Halls. Menel was divided into Nur-menel - the Under Heaven or lesser firmament and Tarmenel - High Heaven or the true firmamant.
The Moon passed through Ilmen on its way around the world, plunging down the Chasm of Ilmen on its way back.