The Transitive Planes: Volume 4
The Astral Plane is well-known as a hub for outer planar travel. It acts as a vital link between the Prime Material Plane and the Outer Planes. Visual characteristics of the plain are drab, yet vast. There is a silvery infinity stretching in all directions. There is no ground and no gravity. Travel is dependent upon time and direction of movement.
Upon entering this plane, the traveler has two choices. They can enter the plane wholly and travel accordingly, or they can choose to leave their body behind on the Prime Material Plane. Choosing the latter, the individual will become semi-solid on the Astral again and they will be bound to their body by a silver cord of infinite length. This cord is very resilient, yet fatal if cut.
Upon exiting the astral on another plane, via a color pool, the traveler will form a new body on the other side. If this body is killed, the traveler will be thrusted back into the astral.
Color pools are very common in the Astral. They are portals leading to and from many different destinations. Destination is always dependent upon color of the pools which are thought to be constant.
The Astral is also the resting place of all pocket dimensions that warp space and weight to produce containers and such on the Primes that are made to hold more than they can spatially.
Large inhabited rock surfaces are known to float around this plane as well, though no other types of demi-planes are known to exist here.