Amon Rûdh is the "Bald Hill" (the meaning of its Sindarin name) that lay south of Brethil in West Beleriand during the First Age. It was a hill of stone, with only deep red seregon (Quenya "blood of stone") flowers growing on top, giving it the appearance of being covered with blood.
Mîm the Petty-dwarf lived within Amon Rûdh with his two sons, Ibun and Khîm. Mîm was captured by a group of outlaws led by Túrin Turambar and forced to reveal the location of his refuge, which was then called Bar-en-Danwedh, the House of Ransom. (Previously, it had been known as Bar-en-Nibin-noeg, the House of the Petty Dwarves.) When it was discovered that Khîm, who had been shot at, had actually been killed, Túrin repented and offered his services to the Dwarf, who from then on tolerated the presence of the outlaws.
Amon Rûdh became the base of operations for the outlaws and with the arrival of Beleg, it became the heart of the area known as Dor-Cúarthol, the Land of Bow and Helm (referring to the Two Captains, Beleg and Túrin), a center of resistance against the forces of Morgoth. Eventually Túrin's location was discovered, and the outlaws were destroyed by Orcs, and the hilltop was covered with blood in truth.