The Swamp of Sorrows (also once known as the Swamps of Sorrow) is a contested territory in the southern part of the Eastern Kingdoms. Among its murk-ridden marshes the green dragonspawn patrol at the behest of their dreaming mistress, Ysera. The great Dragon Aspect has warned of a lurking terror within the Temple of Atal'Hakkar, and her loyal servants are determined to protect the land from the emerging doom.

Far distant from civilization, the Swamp of Sorrows is a stagnant marshland of sucking bogs and weeping trees. The ocean seeps into the fen, making the water brackish and ideal for alligators and crocolisks. Salt deposits encrust fallen logs and protruding rocks. Bog beasts slog through the interior. Despite these dangers, the Horde has taken advantage of the region's distance from Stormwind to establish a colony in the zone. A flight of green dragons guards the Lost Temple, or Temple of Atal'Hakkar, an ancient troll edifice that channels demonic energy and drives living creatures to madness and violence.

Some draenei were led through the Dark Portal by a few unknown leaders with the hopes of finding a new life, and have settled in the Swamp Of Sorrows. Unfortunately, most of them were driven mad due to homesickness, and attack all on sight. They routinely send assassins and saboteurs against the orcs.

The orc outpost of Stonard, built during the First War and rebuilt under Thrall's rule, is the only civilized town in the swamp. It serves as a base for the Horde. While being rather isolated from other Horde settlements, it has gained new interest with the re-opening of the Dark Portal.

Most of the swamp is dominated by nature. Wild beasts like crocolisks and jaguars hunt for prey, and ancient Bog Beasts wander through the land. Aggressive Murloc tribes populate the coast and nearby caves.

The Swamp of Sorrows stands on the eastern side of Azeroth, east of Deadwind Pass, north of the Blasted Lands and south of the Badlands. The only established foot route to it is through Duskwood, then Deadwind Pass, although it is also possible to gain entry from Redridge Mountains by climbing through the peaks south of Render's Valley.

Originally, the Swamp of Sorrows was the northern part of an enormous swampland called the Black Morass. After the fall of the Gurubashi Empire, a renegade faction of trolls, the Atal'ai, fled into the swamp and built a large temple, the Temple of Atal'Hakkar. Ysera of the green dragonflight learned of their evil plans, drowned the temple into the largest bog, and sent several members of her flight to guard the ruins.

Years later, in the southern part of the Morass, the Dark Portal was opened, and the Horde invaded the area. The orcs built two settlements in the Swamp of Sorrows, Rockard and Stonard. These towns, and later Blackrock Spire farther north, were the Horde's main bases during the First War against the humans. During the war, Rockard was destroyed and Stonard was severely damaged.

With the implosion of the Dark Portal during the Second war, the southern part of the morass was separated and transformed into the barren Blasted Lands. The implosion left some groups of draenei on Azeroth, forever changed by the disaster. Most of them went mad from homesickness and the separation from their land, transforming into the hostile Lost Ones. A small group, calling themselves Broken Exiles, managed to escape that fate and struggle along.