Band of Battlehammers
The City of Spiders is a large underground drow city-state in the Upper Northdark, possibly the largest and most well known drow city in the world. It could rival any city in the world, let alone the Underdark.
It is located quite close to Mithral Hall and is connected through tunnels to that settlement. Other tunnels lead to the surface, namely in the Moonwood and on the western edge of the High Forest. Drygully Tunnel is another tunnel leading from the Underdark near Menzoberranzan to the surface.