Selunë was an elvish city which was destroyed during the Great Rift of 884/3.
Selunë; which means "The City of the Moon" in elvish, was a thriving, elvish city which was the Capital of Wyntharë. Today, its ruins lie at the bottom of the Iron Sea.
Selunë was extremely wealthy, as the Grey-Elves traded with both the dwarves of Khûrzhad and Ralani men of Asgamoth.
When the Great Rift occurred, the earth shattered and the seas poured in, and the entire city was consumed and slipped beneath the waves forever. The City Palace was completely destroyed, killing Queen Ariel Alessarë; the ruler of Wyntharë. All three of her Silvarils, which were located within the palace, were also lost.
After the city's destruction, rumors began to spring up that the elves of Selunë had not died, but had simply adapted to their new surroundings. Off the shores of the Sea of Ralas, sightings began of a entirely new breed of elves, with sparkling greenish-silver skin, webbed hands and feet.
Even today, many believe that these "Sea-Elves," now inhabit the underwater ruins of Selunë.