Freedom City (2002)

From the publisher's website:

A Hometown Worth Saving from Evil!

The award-winning Mutants & Masterminds superhero RPG gives you the power to become a superhero. Freedom City gives you a world to rescue from the forces of evil! Called "the greatest superhero setting ever," Freedom City is a fully realized and detailed metropolis that can serve as a home base for your heroes or just one of the many places they visit while saving the world from disaster.

Freedom City includes a detailed history, based on decades of comic book publishing, maps of the city, and hundreds of places and characters to help bring it to life. In its pages you will find:

* The City of Freedom! Everything you need to know about Freedom City, from its history and geography to local color, important personalities, government, and public safety, all loaded with adventure opportunities for your heroes.
* Heroes! Have your heroes join the ranks of the famous Freedom League, protecting the world from their satellite headquarters. Introduce the newest students to the Claremont Academy, where rookie heroes learn the ropes from their elders who have hung up the cape, or meet up with the Atom Family, young mutants in the care of the computerized intellect of their famous scientist grandfather, Dr. Atom; or create all new teams of heroes to rise to fame in Freedom!
* Villains! Face off against the worst criminals Freedom City has to offer: ten supervillain teams, and some one hundred villains, all fleshed out and ready for your heroes to battle! Fight the dark-clad forces of SHADOW, thwart the schemes of the Mastermind, solve the riddles of Conundrum, and hunt the mysterious Jack-a-Knives in the shadows of the West End. When they're beaten, lock them all up in Blackstone Penitentiary or the Providence Asylum.
* Fantastic Places! Go beyond Freedom City and explore the fantastic places the world has to offer, from the mysterious Ultima Thule and the African nation of Dakana, to Farside City on the Moon, Atlantis in the ocean depths, or beyond to the alien Grue Unity or the Terminus, the interdimensional realm of entropy that seeks to consume reality at the command of Lord Omega. Infinite worlds of adventure await you!

Adventure in a true city of heroes...

Freedom City!