 The Dwarves were the greatest miners ever to exist in Middle-earth, building immense halls under mountains where they built their cities.They built many famed halls including the Menegroth, the fairest dwelling of any king that has been east of the Sea, Khazad-dûm, the grandest mansions of the Dwarves, the Elvenking's Halls, and the Kingdom Under the Mountain.In the darkness of Arda already the Dwarves wrought great works for even from the first days of their Fathers they had marvellous skill with metals and with stone; but in that ancient time iron and copper they loved to work, rather than silver and gold.