Door of Night

In J. R. R. Tolkien's fictional universe of Middle-earth, the Door of Night was a place set at the utmost West of Arda, near to Avakúma, the void. It was vital in the cosmology of Middle-earth, forming the border between Arda and the void, as well as being the final prison of the renegade Vala Morgoth Bauglir. Other names of the Door of Night include Moritarnon and Tarn Fui.

In the earliest versions of Tolkien's legends, the Door was created by the Valar as a gateway for the Sun to pass through. The following text describes the creation of the Door:

Thus came it that the Gods dared a very great deed, the most mighty of their works; for making a fleet of magic rafts and boats with Ulmo's aid - and otherwise had none of these endured to sail upon the waters of Vai - they drew to the Wall of Things, and there they made the Door of Night.

In later versions of the story, the Sun and Moon don't pass through the Doors of Night, but sink into Vaiya, the Encircling Seas. The creation of the Doors of Night would have happened at some time to throw Morgoth outside Arda.

The Sun was to pass through the Door of Night as it travelled above Arda. When the Sun passed through the Door, night would fall upon Middle-earth. The Moon would then rise from its resting place and continue on its path over the Earth. The Sun would traverse the border of the Wall of the World, re-entering the world in the East, at the Gates of Morning. At the same time the Moon would be sinking in the West and a new day would begin. At the conclusion of the War of Wrath, when Eärendil the Mariner sailed to Aman to beseech the aid of the Valar, Morgoth was imprisoned outside the Door of Night. The following reference is from The Silmarillion:

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