Shadows in the Void
The Briar Belt
The asteroid belt in the Arcas solar system is tightly-packed rock formations that somehow support the growth of gigantic, tangled brambles. The eponymous briars surrounding the system are strong enough to pierce the hull of those ships careless enough to come into contact with them.
There are stories of ships that strayed off course after passing through a Stygian Gate and have inexplicably find themselves inside the Briar Belt, back in normal space.