The Scrap Yard was an asteroid field named as such in the aftermath of the First Battle of Tovolo, in the Tovolo system. It was so dense that no capital ship could safely enter the Scrap Yard.
Due to the density of the asteroid field, Vegas Station was unshielded, was densely lighted and hundreds of Lysian fighters defended it for the Wyldefire Compact, giving rise to the Second Battle of Tovolo. (Star Trek: False Vacuum: "Scrap Yard Vegas")