The borders of the Mournland are easily distinguished by the dead gray mist that lingers across what were once the political borders of the nation. Why the mists hold in such a defined area is unknown. To the north the Mournland touches against the Cyre River coming off of Scions Sound and emptying into Lake Cyre on the Mournland's eastern border. The Brey River marks part of it's northwest boundary while its border with Breland is only marked by the hanging mist. Similarly in the goblin nation of Darguun the dead gray mist is a constant reminder of the border of the Mournland. To the south lies Kraken Bay and to the east the Blade Desert of Valenar.
As in the Demon Wastes the Mournland is devoid of any real society. A large contingent of warforged have congregated enmasse around a prophetic figure known only as The Lord of Blades. Given the Mournland's hostile terrain the warforged seem to be the only race on the face of Eberron that can tolerate the area since they do not require sleep and have no natural healing capabilities. The Lord of Blades is a fanatical cult that seeks to destroy all races of flesh.
Cyre was the jewel of Galifar's crown in the heyday of the Kingdom. Renowned for its fine arts and crafts and production goods nobles across the kingdom sought pieces of Cyran manufacture. The Entertainer's Guild and Artisan's Guild of House Phiarlan was headquartered in Cyre and spurred the creative forces of the nation. It was Mishann then scion of Cyre who was to be appointed ruler of Galifar after King Jarot's death.
The Last War devastated Cyre, even before the Day of Mourning. Having a central location to all of the Five Nations the landscape was soon scarred by the constant warfare that waged within its borders. Great cities came crumbling to their foundations and public works bore the scars of battle all around. The most devastating of course, was the Day of Mourning which instantaneously eliminated all forms of life within the borders of Cyre. The cause of the Day of Mourning is still unknown and the dead landscape of the Mournland is a testament to the cruelty of the Last War.
Between the events of SY01. The Promised Land and SY16. Symbar, Part II - Eenie Meenie Miney Mo, part of the Mourland was reclaimed by Cyre, splitting the Mournland in two - the Northern Mourn and the Southern Mourn.