Mantol-Derith is a city situated in a huge underground cavern three miles below the surface. It is heavily guarded and protected by strong magic. Its exact location is not known by many. The cavern is naturally formed by water, due to it's proximity to the Darklake, and is filled with waterfalls, pools and streams and its walls are filled with multicoloured crystals and gems. Bridges across the various streams are carved from crystal.
Its exact location was not known by many. It was located on the shores of the Darklake, on the other side of which was the duergar city of Gracklstugh.
Mantol-Derith was located in a twisted cavern 60–70 feet tall and twice as wide. The city was heavily guarded and protected by strong magic. The cavern was naturally formed by water because of its proximity to the Darklake, and was filled with waterfalls, pools, and streams. Its walls were filled with multicolored crystals and gems. Bridges across the various streams were carved from crystal. The city itself primarily comprised trade caravans and campsites.
- Central market
- The market is ringed with giant fungi and merchants set up stalls selling fruit, perfume, woods and spices beneath them.
- There is one huge storage area at each of the four corners of the cavern, for the four factions present in the city.