Geometric Archipelago:Septagon Island
Septagon Island is an aristocratic island in the southeast corner of the Geometric Archipelago, and is the site of The Hunting Ground of Septagon Island. Septagon nobles are leery of the "higher" titles and are suspicious of the possibility of a titles race. As such, Baron/Baroness is the highest rank on the Island. Barons are typically autonomous and will work against each other except during Island-threatening emergencies, which can be discussed and decisions reached based on consent of assembled Barons.
Each Baron has their own primary castle and land area. This land area is divided into either 3 or 4 parcels which are each administered by a Lord/Lady who have quite a bit of control over their area, including having a (smaller) castle within that area but cannot maintain their own armed forces and are expected to obey the Baron who's land their land is contained by.
The campaign will focus on the rough center of the Island, and 5 Baronies within. Every Lord's Castle has a road leading to each other Lord's Castle within their Barony, as well as the Baron's Castle. Each Baron's Castle has a road leading to at least 2 neighboring Baron's Castles. (Among these five, those roads form a ring, and some also have roads leading to castles outside the five.)