An empty plain, it was bordered to the west by the River Narog, and in the east by Sirion. Amon Rûdh lay to the east as well, and many miles to the north were the Pools of Ivrin in Eithel Ivrin. Southeast of the Talath Dirnen lay the Doors of Nargothrond; and beyond rose the Taur-en-Faroth, the Forest of the Hunters above the banks of Narog.
Reaching north and east of Nargothrond, chief city of the Kingdom of Finrod Felagund, the plain was a major buffer between Felagund's land and the threat of Morgoth in his far northern fortress of Angband. The Silmarillion says of the Talath Dirnen:
- "Upon that plain the Elves of Nargothrond kept unceasing watch; and every hill upon its borders was crowned with hidden towers, and through all its woods and fields archers ranged secretly and with great craft. Their arrows were sure and deadly, and nothing crept there against their will"
- —The Silmarillion, page 166
The landscape of the Talath Dirnen was said to be rolling and mostly open. A few patches of forest provided cover for Felagund's rangers, including at the feet of Amon Ethir, the Hill of Spies. The greatest of Talath Dirnen's watchtowers, it was so named for the rangers that guarded it, whose keen elvish sight could descry any approaching enemy.
The Guarded Plain is the place of two significant events of the Silmarillion. Beren Camlost son of Barahir crosses the Talath Dirnen after departing from Menegroth to begin his Quest for a Silmaril. Seeking the aid of Felagund, and knowing the skill of the rangers, Beren holds ever aloft the Ring of Barahir and is eventually waylaid and taken by Felagund's soldiers to Nargothrond. Years later, a bridge is built across Narog from Talath Dirnen to Nargothrond at the order of Túrin Turambar. This helps lead to the sack of Nargothrond at the hands of Glaurung the Dragon and Morgoth's forces. After the sack, Niënor Níniel encounters Glaurung near Amon Ethir and falls under his spell, furthering the curse laid upon the Children of Húrin by Morgoth.
It was sunk along with the most of Beleriand at the end of the War of Wrath.
Translations around the world
|Foreign Language||Translated name|
|Bulgarian Cyrillic||Талат Дирнен|
|Chinese (Hong Kong)||迪能平原|
|Serbian||Талат Динен (Cyrillic) Talat Dinen (Latin)|