The Eithel Ulmo was one of the three principal holy sites for the Dúnedain of the Pelargirean League. While its counterparts—Imrazôr's Hallow and Mount Mindolluin—both stood upon the borders of southern Gondor, Eithel Ulmo was situated in the spiritual and political center of the land: Pelargir (and had, in fact, been one of the principal factors governing that haven's placement). Eithel Ulmo was a dwelling place for the presence of the Lord of the Waters; and when Ulmo drained its waters on behalf of Veantur of Rómenna in S.A. 2331, the now dry well revealed a vast grotto of wondrous design, winch was subsequently delved to become the Hall of the Faithful, But Ulmo preserved a small pool of water in the lowest grotto whence the Captain of the Faithful might go for the purpose of contemplation and counsel. The Eithel Ulmo continued to serve this purpose until the sudden and unforeseen deluge of the Hall in T.A. 1450. Yet Ulmo s presence was still held to linger in those waters, watching over and giving inner solace to die Faithful through the many evils that were to visit them in the course of the age.
More than three hundred feet beneath Tol Aerhir and the waters of the garth lay the source of Eithel Ulmo, a pool of still water in the deepest chamber of the Hall. The four entrances to this chamber were sealed by steel-reinforced doors. Only the chief loremasters possessed keys that would unlock these doors. The well itself was only a few feet deep, and was fed from fissures in the rock. It was here, in the pool, that the Karma of Aldarion once lay.
- MERP:Southern Gondor - The Land