Amon Lhaw was higher than Emyn Muil on the eastern bank of the Anduin while its twin, Amon Hen (The Hill of the Eye) lay upon the western bank. Between these peaks, was the island of Tol Brandir.
This hill may have had special acoustical properties that enabled a person on its summit to hear for miles around (analogous to the Seeing Seat on Amon Hen).
Formerly, Amon Lhaw, was part of the northern borderlands of Gondor, to the extent that a high seat (possibly named the Seat of Hearing) was built there. However, centuries before the War of the Ring; by then, it had fallen under the influence of Mordor.