From the book:
Ancient Cities Special edition is still basically a map product but you will find several innovative aspects like the brief history of this cavern system and illustrations of NPCs and enemies. How you use the given material is entirely up to you. Nothing carved in stone so you can change the history or you can define the sections of this map yourself. With these options you can integrate this city into almost any fantasy role playing game. The given background served as a guideline to design the system, however it contains some useful ideas to set up adventures for your players. Either you need a dwarven city or just a detailed dungeon, Ancient Cities Special edition is what you are looking for.