Elostirion
Elf-tower/s.
White Tower/s.
Built in Second age between 3320-3434. Year 3320 is simply the year Elendil arrived at the coasts of Middle-earth. Year 3434 is the year the Last Alliance marched against Sauron. Elostirion most probably had been finished many years before but I can not find anything else safe to hang it upon.
2 and 3 Age.
Elostirion was the highest tower of the three White Towers upon Emyn Beraid, the Tower Hills. Elostirion was tallest of the three white towers and was the furthest away ( Furthest to the west ) The towers could be seen in the West-farthing and in moonlight the towers shone pale white.
Elostirion was build by Gil-galad and the Elves of Lindon and the Grey Havens for Elendil and stood alone upon a green hill. The name it was given as an remembrance of the tower in fair Tirion. I have not found any precise information of a year for the building but it is stated it was after the fall of Númenor and Elendil`s arrival at the coasts of Middle-earth.
It is stated it was the Elves who built Elostirion but they maybe were not alone in the building of the other White Towers upon Emyn Beraid for in the legends of the Númenorians and their fall it is told how Elendil after his arrival at Middle-earth dwelt at the courses of the Lhûn and Baranduin and at lake Nenuial and how they built at the North Downs, in Cardolan and Rhudaur and " Towers they raised upon Emyn Beraid and upon Amon Sûl and there remain many barrows and ruined works in those places, but the towers of Emyn Beraid still look towards the sea"
But the White Towers was indeed built by the Elves, "It is said that the towers of Emyn Beraid were not built indeed by the Exiles of Númenor, but were raised by Gil-galad for Elendil, his friend" Maybe it all just means that there were ( and are ? ) other towers still standing upon Emyn Beraid.
In other tales it is told how, in the mind of the Númenorians in Middle-earth after the fall of Númenor, thought or believed they could from high places descry the peaks of Taniquetil at the end of the straight road. The straight road was the road of the Elves who would leave Middle-earth. In Elostirion was placed one of the Palantiri brought to Eriador by Elendil. That one Palantiri did not corresponded with the others but was set towards the ocean and the mother stone in Avallónë so Elendil could have a straight look ahead the Blessed Land and Tol-Eressëa. Perhaps this is the reason it was Gil-galad and Elves who build Elostirion for Elendil and the Palantiri, that he indeed should have the sight of the white peak of Taniquetil and the Blessed Land.
The Palantiri in Elostirion at Emyn Beraid left middle-Earth with the same ship as Elrond left with.
In the Earliest Tales Frodo tells of how the Elves used to build high towers with long stairs and how from the top of the tallest tower at Emyn Beraid one could see the great sea and how the Elves kept everything downstairs and only used the top if they wanted to sing or look at the stars.
Related Links.: Battles : Downfall of Númenor. War of the Last Alliance.