
As soon as Cirion came to Minas Tirith he summoned some of his most trusted servants. "You must re-open the ancient path to Amon Anwar. It is long overgrown; but the entrance is still marked by a standing stone beside the Road, at that point where the northern region of the Wood closes in upon it. The path turns this way and that, but at each turn there is a standing stone. Following these you will come at length to the end of the trees and find a stone stair that leads on upwards”.
-Unfinished Tales, "Cirion and Eorl and the Friendship of Gondor and Rohan", (iii) Cirion and Eorl
After the War of the Last Alliance in S.A. 3441, Isildur and his nephew Menedil journeyed with a party of close friends to inspect the borders of Gondor. Near the centre of these frontier lands to the north, Isildur found a mighty hill called Eilenaer. They climbed to the treeless summit and created a level space with a mound on its eastern end. In this mound was laid the casket of Elendil and the hill was renamed to Amon Anwar.
On this spot Cirion, the Steward of Gondor, brought forth Eorl the Young after the battle of Field of Celebrant in T.A. 2510. Here was spoken the Oath that granted Calenardhon to the Eotheod and the hallowed space was split between the two realms. Elendil’s tomb was moved and a new guardianship made of Gondorians and Rohirrim took residence on the hill.
For a time, Amon Anwar was shared equally amongst the two kingdoms, but as the shadow of Mordor grew in the East, Gondor cared less for its Western reaches. The people of the Eastfold were given full control of the hill and it was renamed Halifirien. The seventh and westernmost warning beacon of Gondor was built on the summit and the care of the hill was delegated entirely to the Rohirrim.