The Endless Lake
The Endless Lake is actually the ocean. Dragon-Claw and Wolf-Fang islands, as well as the Isles of Judgment lie within it's water.
Sea of Tears
The Sea of Tears is a massive lake in the center of the Mountains of Dread. Somewhere within the lake are the Lost Ruins. Only the bravest go here, as the lake is home to many unknown monsters. Most adventurers go missing here while looking for the ruins. Don't let it's calm waters fool you.
Lake Edoc'sil
Lake Edoc'sil, or Lake Unconquerable in the common tongue. It is located in the northern fringes of the Twilight Forest. The Lake itself is not entirely water. In the center is a swirling abyss, where all who are sucked in die. It's not a place to go swimming.
Mérisa Lake
The lake cuts across the center of the Gratta Mountains. It lies along one of the best trade routes via water.
The Decus River
The Decus river, or River of Beauty in the common tongue, starts at Lake Edoc'sil. It runs southwest, just north of Vistra. It's waters spill into Mérisa Lake, and start again at the other side, continuing until it runs into the Endless Lake.
The Crimson River
The Crimson River begins in the Lake of Blood. It runs the length of the Valley of Souls, before spilling out it's gates. It passes just west of the small village of Serista, and through the Forest of the Undead before finally reaching the Endless Lake.