Before the Mourning, a spring in the eastern part of Cyre fed the Rushing River as it traced a short but fertile path south to Kraken Bay. The Rushing River is now as dry and barren as the rest of the Mournland, and the location of the spring is marked by the Crimson Water, a stagnant lake of blood-red water.
The shores of the Crimson Water are littered with the bones and corpses of animals and foolish travelers that have strayed into the Mournland and sought to slake their thirst with a drink from the lake. Its depths hold the ruined Cyran town of Eastwood Springs, which once served as a resort town for the leisured classes of Cyre. Even Ikar's Salvage has not dared mount an expedition into the toxic waters to recover any treasures that may lie within the ruins, however.
Despite its toxic waters, however, the lake does support life—of a sort. Water archons (see Monster Manual 2, page 18), their elemental forms the same deep red as the Crimson Water, have been seen around the lake, particularly on the southern shore. Their purpose and origin are unknown, but their presence would seem to suggest a link to Lammania or Kythri somewhere in or beneath the Crimson Water.