Stellar Garden of Ulmac
At the edge of the Vortex Spiral Galaxy is a stellar cluster that is home to several sentient species. The star cluster is encased within a large cloud of interstellar dust. The cluster is known as the Stellar Garden of Ulmac by it's inhabitants. "Ulmac" specifically is the name given to the massive cloud of interstellar dust the stars all reside within. Regardless of this, the cluster and all the stars and planets within it are collectively known as "The Garden".
The interior of The Garden is approximately 72 light years across at it's widest point. Estimates at the size of The Garden including the stellar nebula it resides in put it at over twice that amount (160 light years across).
Traveling through The Garden
Travel between the stars is accomplished through use of jumpdrive technology.
The jump-drives employed by the denizens of The Garden react poorly with the condensed interstellar matter that makes up the Ulmac nebula. Ships that have attempted to jump into the nebula have been crippled or destroyed. Travel through the nebula at sub-light speeds would take hundreds of years.