Mount Orodruin is J.R.R. Tolkien’s fictional Mount Doom, where the One Ring is destroyed. The volcano stands in Mordor, close to Sauron’s stronghold of Barad-dûr, and its fires are the only ones capable of undoing the Ring.
Frodo Baggins and Samwise Gamgee reach Orodruin after crossing Mordor with Gollum as their guide. At the Crack of Doom, Frodo claims the Ring rather than willingly casting it away. Gollum attacks him, bites off his finger and falls into the fire while clutching the Ring, causing its destruction.
Orodruin’s significance comes from its connection to the Ring’s creation. Sauron forged the Ring in its fires during the Second Age, putting a large part of his power into it. Mount Doom is therefore not merely a convenient volcano; it is the place where the Ring’s power can be reversed. “Orodruin” is the Sindarin name generally translated as “Mountain of Blazing Fire.”