Trehaug is the chief settlement of the Rain Wild Traders, on the shores of the Rain Wild River, a number of days' travel up from the river mouth. It is located approximately three or four days' travel down from Cassarick.
Unlike other cities in the Realm of the Elderlings, Trehaug is not built on the ground. It is built up in the trees, consisting of platforms around the trunks of trees. To get from one level of the city to another, folk must either ascend steep stairs circling the trunks or pay for the use of a ballasted elevator-like cage. The various trees are linked by foot bridges, trolley spans and similar constructions. The further up a trunk a structure is, the more lightweight its construction. Wealth and fortune are typically judged by how close to a trunk someone lives.
The poorest sections typically shake even in the lighter quakes common to the Rain Wilds.