The Dreamlands

The Dreamlands are a seemingly infinite realm of fantasy, imagination and spirit, held to be the substance and body of the Primordial Duroon itself. The relationship between the Dreamlands and the physical realms of Thaelis-Y'Aada is contested between theological schools, but it is known with certainty that the two dimensions are closely inextricably linked. The Dreamlands are also called the Astral Plane, as it is known that these fantastic fields are where the dreaming minds of mortals and gods coincide.
The Dreamlands are the home of spirits, and contain within them the influences of all planes, both higher and lower. The easiest way to access other planes of existence for mortals is to travel to them while dreaming, where conversation with entities living there can be achieved with little threat to the sleeping body in the physical plane. To actually project oneself fully into the Dreamlands, requires the application of advanced magic. The Dreamlands are thought to be truly timeless, but were, so say the greatest of the world's dream scholars, largely inaccessible during the Age of the Ancient Ones, a fact which some believe may have led to their eventual downfall.
=== Terrain ===
The Dreamlands, quite alien in their properties to those of the waking world, are fluid and everchanging in their topography. Since the landscapes here are the collective formations of every conscious mind of mortal, spirit and god, they are in a constant state of material flux as sleepers' subjective dreams shift, minds awake from slumber and others lapse into it. Areas may closely resemble replicas of locations within the physical plane, but blend into areas completely unknown to Thaelis-Y'Aada. Solid earth may suddenly give way to great gulfs of astral cloud, meadows of fire or abysms of black chaos. The realms of divinities and great cities built by giants and other great spirits exist here, and are fully tangible to those who tread the dream in sleep or through projection of their consciousness. 
=== Inhabitants ===
The Dreamlands are populated by every manner of creature the imaginations of men, gods and Primordials can conceive of. Species utterly void of presence in the physical world exist here in abundance, and their biology is completely unfathomable to observers. All manner of spirits dwell here in material form, and can be touched normally by dreamers. The gods and their servants roam the landscape, working their politics across the changing landscapes through inscrutable means. Many great sorcerers and magi also retain rulership and holdings within some astral lands.