The Astral Sea

The Astral Plane (also called the Astral Sea or the Plane of Dreams) is an expanse of stars, silvery winds and violet-hued stones drifting through endless space. The Astral sea's native denizens include Somnian elves, Illithids, Aboleths, and Flumphs.

Dream Magic

The Astral plane has a unique, mystical property of magic-made-real. Any who wander this realm can conjure from their minds eye any thing or reality of their choosing, given enough mental fortitude. Indeed, highly intelligent creatures and trained wizards can drift through the sky here like birds on the wing, or equally conjure swords, carts, or entire castles without resorting to traditional spellcraft. Visitors beware however, for this brand of magic attracts the lecherous magic-drinkers of the Astral Sea, the Dream Eaters.

Notable Locations

Tu'narath. The only known city in the Plane of Dreams, inhabited predominantly by Somnian Elves (Githzerai and Githyanki). Hosts a large population of Aboleths, Illithids, Flumphs and Beholderkin. The city itself is built upon the drifting remains of the long-dead titan Tu'narath.
Shipbreaker Belt. The only location within the Astral Sea whose location remains static, Shipbreaker Belt is used as a point of reference for sailors of the silver seas. It is a large ring of drifting asteroids many miles wide.
The Shackles of Eternity. An extra-dimensional prison which consists of metallic round cages chained to a small star.
The Infinite Library. A citadel of parchment and magic which houses every scrap of knowledge be it forbidden, secret or not yet written. It is managed by a mysterious curator. Those who peer recklessly into its endless knowledge are claimed by the Keepers, or succumb to madness.
Eldritch Reaches. A span dominated by an unknowable higher power.
Cosmic Milk. A swath of thick astral sea that slows or ensnares ships passing through.
Field of Shattered Stars. A domain of white-fire stars drifting lazily through the Astral Sea which have been known to explode violently, casting chunks of starmetal and raw gemstones into the Sea.

Navigation

Passage through the Astral Sea is complicated. The distances and threats are great, and the atmosphere is such that a normal ship (seabound or otherwise) can easily sail. Teleportation magic is semi-common, but the chaos of the Astral Sea has been known to throw more than one wizard astray. Thus the inhabitants of the Astral Sea outfit their ships with Spelljammers. Ornate thrones paired to matching crowns (or other jewelry) that allows the ship's captain to propel their ship with their magical ability. In recent years, the Spelljammers have been modified to accept Dream-magic wielded by Astral Projections and native inhabitants of the plane, without the need for traditional arcane inputs.
Given the ever-changing nature of the plane, typical cardinal directions are more or less meaningless. Specific stars remain in place however, so inhabitants of the Astral Sea have developed an alternative, three-dimensional compass rose with the following primary directions:

Starward

Moonward

Semi-starward

Semi-moonward

All of the above, in "anterior" form.

Type

Dimensional plane