Black Mirror Lake has a large coal deposit at the lake’s source. This deposit serves as a natural filter making the lake’s water especially pure, but also coloring it slightly black. Combined with the calm surface of the lake this black color earned the lake its name. Black Mirror Lake supports the town of Balin’s Holt. The settlement was built upon the ruins of Fangaroot, once the Dwarven capital before the Age of Monsters. The coal of Black Mirror Lake prevents large fish from growing but provides valuable fertilizer for the farms along the lake’s coast. Balin’s Holt is well known for the large root vegetables and squash grown from Black Mirror Lake’s silt.