Spelljammer: The Astromundi Cluster

The Astromundi Cluster described a unique crystal sphere composed of free-floating asteroids. The sphere's weak barriers encourage free passage between the Prime Material Plane and the Inner Planes, resulting in a bizarre and potentially explosive mix of creatures. The "Celestial Almananc" lists dozens of locales, from the outcast colony of Chakarak to the orchard-laden Boyarny. The "Astrogator's Guide" provides game statistics for the Doombat and other new ships.