Running along much of Mendev's south border with Numeria the Egelsee River is an important geographical feature for Mendev. The river provides the capital city of Nerosyan with all of its fresh water and the abundant fisheries found along the Egelsee's length help keep Nerosyan's population feed. Despite this the most important feature of the river is a unique mineral that collects in its silt called Nexavar. This mineral actually counteracts the corrupting influence of the Worldwound meaning that the southern length of the Sellen is not corrupted by demonic influence and that no aquatic demons can swim down its length to the lands it touches or even worse the Inner Sea. If it wasn't for the Egelsee River who knows how far the demonic taint could have spread. Nexavar is so effective at stopping corruption that it was used in the creation of the Wardstones that help keep the expanding Worldwound in check.