Cracks of Doom

The Cracks of Doom were the fiery chasms within Mount Doom (Orodruin), the volcano in the heart of Mordor. It was the one place in all the world where the One Ring could be unmade, for it was in those very fires that Sauron had forged it in the Second Age.

Description

The Cracks of Doom lay within the Sammath Naur, the Chambers of Fire, a passage bored into the side of Mount Doom. Within was a great fissure opening upon the molten fires beneath the mountain. The heat and fume of the place were terrible, and the mountain's eruptions waxed and waned with the will of Sauron.

The Forging of the Ring

Long before the War of the Ring, Sauron had wrought the One Ring in the fires of Orodruin, pouring into it much of his own native power so as to rule the other Rings of Power. Because so much of himself was bound into it, the Ring could be destroyed only by the same fire that made it, and no other heat or craft could melt it.

The Destruction of the Ring

The whole quest of the War of the Ring turned upon reaching the Cracks of Doom. Frodo and Samwise crossed the desolation of Mordor and climbed the mountain to cast the Ring into the fire. At the very brink, Frodo was overcome by the Ring's power and claimed it for his own. But Gollum, who had followed them, seized the Ring, biting it from Frodo's finger, and in his triumph fell with it into the Cracks of Doom.

So the Ring was unmade. With its destruction Sauron's power was broken forever, his fortress of Barad-dûr collapsed, and the long Third Age drew to its end.