The Wrenhaven River is a major river that runs through Dunwall. Corvo Attano and the Loyalist Conspiracy use this river to travel to the Hound Pits Pub, as well as the locations of all major missions throughout the game.
Samuel Beechworth is thoroughly familiar with the Wrenhaven  and is employed by Farley Havelock to navigate it. Samuel reveals to Corvo that he has seen things of a strange and magical nature on the river, such as mysterious lights and faces in the water.
The river is also known for dispersing strange artifacts along the shore, such as runes and bone charms, which are believed to be the remains of an ancient city that once stood on the land Dunwall now occupies.
In the wake of the plague, many of the river's bridges are derelict and collapsing (with Kaldwin's Bridge standing as a notable exception). Many corpses are dumped into the river, with the resulting smell not being a pleasing one.
The Wrenhaven River Patrol enforces the law across the river and its tributaries.
- The Wrenhaven River appears to be strongly inspired by the River Thames.