J.R.R. Tolkien called the fiery mountain where the One Ring was forged Mount Doom.
Mount Doom stands in Mordor and is the volcano where Sauron forged the One Ring. Its fires are essential to the Ring’s destruction, because ordinary weapons cannot unmake it. Frodo and Sam must therefore reach the Cracks of Doom inside the mountain during the final stage of their quest.
Tolkien also gives the mountain the Sindarin name Orodruin, meaning “Mountain of Blazing Fire.” Mount Doom is the familiar English name used throughout much of The Lord of the Rings. These are two names for the same landmark, not separate mountains.
The Ring is finally destroyed when Gollum bites off Frodo’s finger and falls into the fire while holding the Ring. The resulting destruction of the Ring brings down Sauron’s power and destabilizes Mordor.