From Dragon Eye Atlas
The massive lake at the core of Auseka, and in the heart of Vericum. It is over 600 km in total length, and about 50 km across in most places, making it large and deep enough for ships that would otherwise be found on the open seas. Which the lake seems to be for those nearby, as the opposite coastline is only visible in the more narrow southern extent.
Lake Erisai is the largest freshwater lake in the world, and is fed by more than a dozen rivers.
It is possible to reach the ocean from Lake Erisai by navigating the Sisenand and Ardabur rivers, which flow out from it and towards the ocean. No ocean-going ships would manage it, however, as the Sisenand flows in shallow and fast rapids in several parts, making it impossible to traverse its entire length with a large ship.
The lake is rich in fish and other wildlife and it attracts birds from afar. The steep cliffs that surround it in many places reduce the land animals that come to drink, which they could as Lake Erisai is a fresh water lake.