Arda Marred is the name given to the world as it is: the world after the wars of the Valar and Melkor, and the dispersing of Melkor's fëa in the entire world. It is this world from which are formed the hröa of the Children of Ilúvatar, and therefore it is at times a cruel and evil world with plagues, extreme colds, heat, and other concepts which do not exist in Arda Unmarred. Arda Marred also broke the design of Elvish immortality: in Arda Marred Elves slowly fade, until at last they are naught but wraiths. Only in Valinor was this fading delayed, which is one reason all Elves had no choice but to go to Valinor in the end. One of the special abilities of the Rings of Power was that they could delay time, and as such were used by Elrond and Galadriel to preserve their realms. After the loss of the One Ring the Elves had no choice left and therefore in the Fourth Age the last Eldar left for Valinor.