The Book of Destruction
The Forsaken Swamp is a huge expanse of murky water and mud, decay and death, a place where many have tried to survive and all have failed. The landscape is covered nearly completely in several inches of tepid and diseased water, with small hilltops poking out covered in gray spongy moss. Very few plants and even fewer animals can survive here, as there is always an overcast gray and dreary sky, frequent windstorms, and a bitterly cold wind from the north that flash freezes large stretches of the swamp at a time. The lost ruins of many cities and temples lie half submerged in the mire, preserving forever their failure.
NOTE: It is nearly impossible to scrounge up food in this area, requiring a DC 25 Survival check just to get one meal. Adventurers properly equipped to dig have an easier time of it, with the DC lowered to 20.