| Category | Swamps |
| Continent | Brucrumus |
| Region | Lands of Purity, Troll Bogs |
| Map | Sinarag Swamp |
Sinarag is a huge swamp covering territory in the Troll Bogs and the Lands of Purity. It was created over thousands of years from otherworldly water pouring out of the Radullu Rift. By the Horgon Era, the water, sediment, and vegetation coming through this rift had turned a large swathe of the Troll Bogs into wetlands. Sinarag is the largest of these wetlands.
Sinarag is home to yuan-ti, Lorhazi, scrag, black dragons, trolls, catoblepas, will-o-wisps, crimson deaths, and other wetland horrors.
In the Lith-Crillion Era, the Pyramid of Alchemy was built in the southern reaches of Chen'gom. The labs in this half-submerged structure were used to produce an array of new lifeforms that are unique to the Troll Bogs. Most are variations of species native to Sinarag, while others are totally new. The Lith-Crillion researchers also started a program to selectively breed trolls in the hopes of increasing their intellect and perhaps reducing their violent tendencies. These programs did not come to fruition, with them concluding that it would take too long - several thousand years by best estimates. It is generally believed that Lith-Crillion working on these things were inspired by the demon labs at Aša Abrai.
Sinarag is claimed by Ningizzida. This is a tenuous claim, with borders very difficult to control even by the empire's water-dwellers.
The disease and viciousness of those living in this vast swamp are such that the place has generally been avoided by conquerors. The undead armies of the Black Tide of Thasmudyan avoided it, as did the holy empires of the Lands of Purity. Virulent diseases, sink holes, acid pools, insect infestation, poison gases and a host of monsters keep even the adventurous from this area.