From the back of the book:
Join Sanctuary, a dignified club for paranormals from both sides of the law. The grounds of Sanctuary provide an ideal refuge from superhero battles of the hostile world and a violence free safe haven for its members. Only here can you catch the latest movie without fear of being clobbered from behind. A cross between a boarding house and a "gentleman's club," Sanctuary is a place for paranormals to socialize with their own kind. Imagine playing chess with Doctor Destroyer. Arguing politics with Professor Muerte. Or attending a lecture by your arch-enemy. Now all this is possible.
Neutral Ground fully details Sanctuary: its background, floorplans, and personnel.