North and west from Minas Tirith, a low-lying chain of hills ran through the Drúadan Forest in parallel with the eastern White Mountains. Beyond the forest, the easternmost of these hills rose to form a great isolated height north of the Grey Wood and Mindolluin. This was Amon Dîn, the so-called 'Silent Hill'.

To a traveller passing north along the road from Minas Tirith, Amon Dîn would rise to the left after some twenty-five to thirty miles. With a wide view of Anórien, Cair Andros and North Ithilien across the Great River, it was natural that the Gondorians should make it a guard post, and indeed it was fortified from early in Gondor's history.

At some point the camp on Amon Dîn was equipped with a beacon to warn the people of the surrounding country of danger. This was the first of a series of beacons to send warning and call for aid. After that on Amon Dîn, beacons were built on Eilenach and Min-Rimmon, and more beacons were added as the years passed. At the end of the Third Age, a line of seven beacons stretched from Amon Dîn as far west as the Halifirien on the borders of Rohan.