Númenor is the fictional island kingdom destroyed in Tolkien’s tale The Downfall of Númenor.
In Tolkien’s mythology, Númenor was a great island realm granted to Men who had aided the Elves during the First Age. Its people enjoyed long lives and great skill, but later kings became increasingly resentful of mortality and suspicious of the Valar.
The kingdom’s destruction came after its ruler, Ar-Pharazôn, sailed west to challenge the power of the Valar. Tolkien’s account echoes elements of Atlantis while remaining part of his own history of Arda. Survivors founded the kingdoms of Gondor and Arnor in Middle-earth.