|"The Coming of Glaurung" by Alan Lee|
|Other names||Guarded Plain|
|Location||Between the Narog and Sirion/Teiglin Rivers in West Beleriand|
Talath Dirnen, the Guarded Plain, was the forested empty land roughly between Narog and Teiglin in Beleriand and belonged to the Realm of Nargothrond. In its eastern part was the lone hill of Amon Rûdh.
The plain was guarded by rangers and hidden towers. When Sauron conquered Tol Sirion, the West Beleriand was open to his forces. Although uninhabited, the plain was defended by scouts and spies of Nargothrond, the Haladin of Brethil, and the Gaurwaith. Under the Two Captains, the Gaurwaith controlled the area around Amon Rûdh, named Dor-Cúarthol after The Helm and The Bow.
After the capture of Túrin Turambar, the plain was ravaged by Orc raiders and King Orodreth protected Nargothrond with ambushes, not wishing to draw Morgoth's attention to his hidden city. That was until Túrin, now known as Mormegil, persuaded him to fight openly, and they managed to clear the Plain from Orcs. The Plain was lost after the Battle of Tumhalad and the fall of Nargothrond.
- J.R.R. Tolkien, Christopher Tolkien (ed.), The Children of Húrin, "Of Mîm the Dwarf", p. 127
- J.R.R. Tolkien, Christopher Tolkien (ed.), The Silmarillion, "Map of Beleriand and the Lands to the North"
- J.R.R. Tolkien, Christopher Tolkien (ed.), The Children of Húrin, "Túrin among the Outlaws", p. 110
- J.R.R. Tolkien, Christopher Tolkien (ed.), The Children of Húrin, "The Coming of Glaurung"