Gobwin Knob is the current capital and only city of the Plaid tribe.
Gobwin Knob is called by Stanley the Tool as the "toughest defensive position in the known world". It is located in the caldera of an extinct volcano, in which there is a honeycomb-like maze of tunnels originally created by Sizemore Rockwell. Unfortunately, the tunnels were originally dug for the purpose of mining gems (thus generating income for the faction's treasury) and were not designed for defensibility. If necessary, tunnels could be collapsed to block invaders, but Sizemore's opinion is that collapsing too many of them would cause the literal fall of the city.
Within the city is the Tower of Efdup, in which the leadership and casters of Gobwin Knob reside.