The Filthy River of Styx

AKA-
 * River of Hate
 * Gulf of Heresy
 * Reservation to Tenebris Hiems

The River of Styx is the open Reservation of Tenebris Hiems. Those that go here become damned with darkness due to the River's Filth of Hate. The Amortal Father of Death was named after this place for mutilating his own soul to a state of nothingness.