Haven's northeastern expanse is dense with tributaries that drain into the region's main waterways. Twin Rivers is the most prominent of these, though its proximity to the Oldwalls and occupation by the Bronze Brotherhood make it an infrequently-visited location. This location is the precise point where the Crossing river splits into its two branches.
Points of interest
You are asked to join the fray against the Bane immediately after arrival, by Brother Caelus. After dealing with the Bane (or both the Bane and the Bronzemen), you are free to explore.