The hidden Elvish refuge ruled by Elrond in J.R.R. Tolkien’s Middle-earth is Rivendell.
Rivendell is also called Imladris, an Elvish name meaning “Deep Valley of the Cleft.” Elrond establishes it in the Second Age after the destruction of Eregion. Its protected valley lies east of the Misty Mountains and becomes a place of healing, learning, counsel, and refuge.
Bilbo reaches Rivendell during the journey described in The Hobbit. In The Lord of the Rings, Frodo is taken there after being wounded by a Nazgûl, and the Council of Elrond later decides that the One Ring must be destroyed in Mount Doom.
Rivendell is distinct from Lothlórien, another major Elvish realm ruled by Galadriel and Celeborn. It is also not a city of Men such as Minas Tirith. Tolkien’s descriptions present Rivendell as both a physical valley and a surviving center of ancient Elvish culture.