Punampu, who’s inhabitants call it the Anciently Dignified and Resplendently Aged City of the Punampu, was originally a very large and splendid city, the capitol of a forgotten kingdom, which, in age, has declined to a somewhat less grand state.
The underlying terrain of the city defines it. It is a large, broad mound. This cluster is as strange to the Kerrenese as Venice or a sunken city is to most Westerners.
There is a place where only the foolhardy and the greedy dare to go. Why do I say foolhardy, because of all of the poor souls who have entered that dark place…none have yet to return.
Squish, Squish. Squish.
Bogmoors has been here for 721 years. It started with an ale stop for the Imperial invaders. From there it has been a similar stop for every wave of invaders since then, as well as every local for a good walk’s distance.
With a huge number of sacrificial victims, another realm long ago secretly bound a Prince of the land spirits, Iorstonn by name, thus ensuring the fertility, and improving the magical defences, of their realm. But binding that Prince to one spot has disrupted the weather and magical patterns (ley lines?) over half the continent. Things have become bad enough that a coalition has been formed to rectify the situation, once divinations have established the cause.
Your party is one of the teams assembled to do the rectification: find the binding object and steal it ("so that we can destroy it here in our realm, of course"...*) or destroy it over there. Presumably the Prince will be grateful to his rescuers and angry at the binders, but with a greater spirit like Iorstonn one can never be sure: such beings are "tricksy".
* Of course, the rulers of our realm might want to control Iorstonn for their own ends...