Mount Doom is the sacred mountain where J.R.R. Tolkien’s One Ring must be destroyed.
Mount Doom is the volcanic mountain in Mordor whose fires forged the One Ring. Because the ring was made there, it can be unmade only in the same destructive fire. Frodo Baggins and Samwise Gamgee therefore travel across Mordor to reach its summit and the Cracks of Doom.
The mountain’s Elvish name is Orodruin, meaning “Mount Doom” or “Mountain of Blazing Fire.” Tolkien also uses Amon Amarth, a Sindarin name meaning “Mount Doom,” especially in later descriptions. These are names for the same landmark, but the English answer requested here is Mount Doom.
Mount Gundabad is a different mountain in the north, associated with the Orcs. Amon Amarth and Orodruin are plausible alternatives because they are authentic Tolkien names, but they are not the standard English title used in the question.