Númenor is the fictional island kingdom that sank in J.R.R. Tolkien’s account of the Second Age.
Númenor was an island realm in the Great Sea, granted to the Men who had aided the Elves during the wars of the First Age. Its inhabitants became powerful sailors and founded colonies and kingdoms in Middle-earth, including Gondor and Arnor through the brothers Elendil, Isildur, and Anárion.
Over time, Númenórean fear of death and envy of the immortal Elves intensified. Under King Ar-Pharazôn, the kingdom challenged the power of the Valar and sailed west toward Aman. Tolkien’s mythology describes the island’s destruction and submergence as a world-changing catastrophe, after which the surviving Faithful established the realms in exile.
Númenor’s fall resembles the Atlantis tradition, but Tolkien gave it a distinct history, language, genealogy, and religious conflict. Gondor was not the sunken island; it was one of the kingdoms founded by Númenórean survivors.