Seven discrete chapters each detail a specific size of city; a thorp, hamlet, village, small town, large town, small city, and even a large city are all described not only with maps, but also with unique personalities that guarantee PC interaction.
Later chapters refer to earlier ones, so that some of the inhabitants of the thorp show up in each of the larger communities, playing similar roles in every instance. This makes it easy to pick the size of the city you want and make use of as much of Seven Cities as possible.
Seven Cities is also designed to help tailor any city to work better in your campaign; add new life to it, and let it throb with the pulse of the people who make it their home.
Like all Penumbra products for the D20 System, Seven Cities gives you material adaptable to any fantasy campaign, whether it be a published setting or a world of your own creation.