Khazad-dum was the greatest of the Dwarf realms in Middle-earth. Its vast and beautiful halls lay under the Misty Mountains. From its mines came great riches and it was the only source of the precious metal called mithril. But a Balrog slept in the deeps beneath Khazad-dum, and when it awoke the Dwarves were driven from their home. The halls of Khazad-dum were taken over by Orcs and other evil creatures and it became known as Moria, the Black Chasm, and was a place of fear and dread. Khazad-dum was located in the Misty Mountains under the three Mountains of Moria - Cloudyhead, the Redhorn, and the Silvertine. On the eastern side of Khazad-dum was the Dimrill Dale where the lake of Mirrormere lay. On the western side was the region known as Eregion, or Hollin. The halls of Khazad-dum stretched about 40 miles from east to west.