Amon Ethir was a hill, which was raised by the folk of Finrod, in the plain of Talath Dirnen (The Guarded Plain), near to the Doors of Nargothrond and the River Narog.

Its summit was free from trees, allowing the watchers of Nargothrond to guard the entire plain from atop it. So it was the hill got its name, Amon Ethir, 'Hill of Spies'.

After the destruction of Nargothrond Amon Ethir was the place where Nienor encountered Glaurung the Dragon for the first time. There Glaurung put a black spell on Nienor, which caused much grief to befall her.