The Halls of Awaiting in Aman (somewhat conjectural)¹

The great silent Halls that lay on the western fringes of the world, overlooking the wide Outer Ocean. Also called the Halls of Waiting or the Halls of Mandos, they were kept by the Vala originally known as Námo, but who is more commonly named Mandos from his association with these Halls. There also dwelt Mandos' spouse Vairë, who wove the history of the world of Arda into long tapestries that adorned the Halls.

It was to these Houses of the Dead that spirits - known as fëar in Elvish - were gathered after their deaths. There they awaited the judgement of Mandos the Doomsman of the Valar (so giving his Halls the name 'Halls of Awaiting'). It was said that none could escape from the Halls once placed within (and as they were able to hold Melkor, acknowledged as the most powerful being in Arda, this was evidently true).

For the immortal Elves, if Mandos judged them worthy and they themselves wished it, their spirits could be re-embodied in Aman. Depending on their deeds in life and their willingness to repent, Mandos could choose to delay this fate, and in some extreme cases a spirit might be confined within the Halls of Awaiting forever. The spirit of Fëanor, chief of the rebel Noldor and leader in the Kinslaying, was said to be one of those who would never return from Mandos.

The spirits of mortal beings, or at least of Men, were also gathered in the Halls of Awaiting, but their fate was different from that of the Elves. After their time in the Halls, those spirits would depart across the Outer Ocean and beyond the boundaries of the world, and even the Valar (apart from Manwë and Mandos) did not know what their final fate might be.

For those who were not of the Children of Ilúvatar, it is less clear whether their spirits were gathered into the Halls. The Dwarves claimed that this was the case, and that they entered the Halls in their own place. There they would await the time of Arda's remaking when they would aid their own creator, Aulë, in the rebuilding of the world. (It should be said that this belief was not universally held, and the fate of the spirits of Dwarves - if indeed they had spirits in this sense - is not certainly known.)

As a judge of the dead, Mandos was almost completely implacable. After the death of Beren, however, Lúthien was able to sway his judgement. As Man and Elf their fates would have seen them parted forever, but the Doomsman relented. They were both returned to life for a time as mortals, so that their fates would be intertwined. This was a unique event: Mandos had never been known to show such pity beforehand, and it is said that he would never again release a spirit from its judgement in the Halls of Awaiting.