 To the northeast, by the river Anduin, are the Emyn Muil, with watchtowers on the hills of Amon Hen and Amon Lhaw on opposite banks of the river, and the Gates of Argonath at the northern entrance into the straits of Anduin as a warning to trespassers.Further down the river are the hills of Emyn Arnen.The capital, Minas Tirith, lay at the eastern end of the White Mountains, built around a shoulder of Mount Mindolluin.