Elostirion

The -tirion of Elostirion's name can be safely interpreted as 'watchtower' (in a special sense that it held the Elendil Stone, which granted a view of Tol Eressëa in the lost West). The el- element is either 'Elf' or 'star' (with 'Elf' more likely, as the towers of the Tower Hills are elsewhere called 'Elf-towers'). Finally the connecting -os- typically refers to walled or fortified buildings or cities, hinting that the tower was protected by its own encircling wall.

Most of the locations shown on this map are well established, but the exact position of Undertowers is open to question. We know that it was in the Tower Hills (Emyn Beraid on the map), and the fact that it was the most important settlement in the Westmarch probably places it on the eastern slopes of those hills.