Sweetwater
From DQWiki
Named for its unique taste, the Sweetwater is said to run from the very center of the Sea of Grass all the way to Confederation Bay.
It is fed within the region portrayed by the Swan River, the Wandle Rithe, the Gilder Rithe, the Champion River, and Rithe Regar.
Over a mile wide through most of its course, the Sweetwater is uncrossable except by ferry or at one of the few fords where a horse can be swum across.
The old maps show the Sweetwater as the Schilkarsi River with its origin in a mountain chain deep in the interior of the continent.
The source of the Sweetwater is believed to be a spring with powerful healing magics.