It’s a huge setting to fit into such a little book. As part of the Tales of Zobeck patronage project, I wrote the first sourcebook to describe the Free City of Zobeck, a mercantile city easy to drop onto a river in any campaign. The Gazetteer takes a deep look at the two of the topics that define the city — Clockwork Magic and the kobold ghetto. And just for good measure it covers the Gearforged PC race, the city locales, a little bit of history, and some clockwork monsters.
If you were a patron of this project, of course, you already have your copy. Tell folks about it in the Forum.