A Mansion is a Nonman stronghold, city and fortress, typically subterranean or built into the interior of large mountains or hill. At their height the Nonmen established dozens of such settlements across Eärwa, stretching right across the continent.

The Nine Great Mansions before Arkfall.
The centres of Nonmen culture and society were the Nine Great Mansions, named and located as follows:
- Siöl - Located in the north-eastern Great Kayarsus Mountains, guarding a series of fortified passes leading to the eastern continent of Eänna. Some historians believe that Siöl may be the location of the Breaking of the Gates and the entry of Men into Eärwa in substantial numbers.
- Nihrimsul or Nihrimsûl - Located on the southern-most spur of the eastern Yimaleti Mountains. Founded independently from Siöl by the ancestors of the Nonmen.
- Ishoriöl or Ishterebinth - Located west of the Demua Mountains and south of the Leash. Founded by Siöl.
- Viri - Located south-west of Nihrimsul under the mountainous peak of Antareg in the Urokkas, overlooking the Neleöst. Founded by Siöl.
- Illisserû or The Lighthouse - Located under the Betmulla Mountains, founded by Siöl. Later renamed Orovelai, the stronghold of the Swayal Compact in the years after the Holy War. The second Mansion to be settled by men (or, in this case, women).
- Cil-Aujas - Located under the mountainous peak of Aenaratiol in the Osthwai Mountains. Founded by Siöl.
- Curunq - Located in the Araxes Mountains. Founded in the second wave of Nonman expansion from those Mansions founded by Siöl.
- Incissal - Located near the modern city of Domyot in Zeüm. Founded in the second wave. The first Mansion to be settled by men.
- Cil-Aumûl - Located in the Hinayati Mountains. Founded in the second wave.
Other Mansions were founded, such as the one found just a few hours from Shimeh, but these were of a significantly lesser order and generally held fealty to one of the Nine.
Siöl claimed to be the First Mansion, the ancestral home of all Nonmen, founded directly by the progenitors of the Nonmen race in a time so ancient as to defy reckoning. For this reason Siöl took the title "House Primordial", a term used to refer to both the Mansion and its ruling family. Extant records support this, tracing a line of founding from Siöl to first Ishoriöl, Viri, Illisserû, and Cil-Aujas. Those Mansions turn later founded Curunq, Incissal, and Cil-Aumûl. Nihrimsul was founded separately and outside of this line of descent, although its claim to have originally founded Siöl (and thus being the true House Primordial) was hotly denied by Siöl.[1][2]