From Tolkien Gateway
Matěj Čadil - Noirinan

Noirinan, or The Valley of the Tombs, was located between the southwest and southeast ridges of the Mountain Meneltarma on the island of Númenor.[1] The shallow valley held the tombs of the Kings of Númenor, cut into the rock of the mountain. In Noirinan was also the spring of the river Siril, the main course of water which flowed across the island of Númenor.[2]