Headquarters & Hideouts (2002)

From the Introduction:

Headquarters. Hideouts. Lairs. Labs. Be they caves, mansions, space stations, or extra dimensional hidey holes, bases of operation have long been a staple of superhero stories. The best such places were as much characters as the heroes and villains of the tale, taking on a personality, style, and feel of their own. A hideout spoke volumes about its inhabitants, from the trophies kept there to the location of the hideout, important facets of the owner could be discerned. All in all, headquarters are much more than places to simply hang your cape and mask.

This book contains additional rules for creating headquarters, new rules for trainable skills and feats, and the details on a number of headquarters including history, abilities, inhabitants and maps. Also included is an adventure to demonstrate how to use one of these locations in your campaign.