The Bitter Sea
The Bitter Sea, formally known as the Crystal Sea, is a body of water east of the Land of the Dead, north-east of Lybaras, and south from the Plain of Bones. To the north-west, it is connected by the Straits of Nagash to the polluted Sour Sea.[1a]
The sea most likely got its name from the contaminated waters high up in the Worlds Edge Mountains, where the Sour Sea is located, its waters being polluted by huge amounts of warpstone that run off from the warpstone fragment that struck Cripple Peak many centuries ago, as well as the pollutants caused by the River Ruin that feeds into the Sea of Dread.[1a]