The Barrens was a region within the Alpha Quadrant that was surrounded by a subspace node where no star could exist due to a "curved bubble" of space-time.

Emory Erickson, the inventor of the transporter on Earth, travelled on board the Enterprise to the Barrens in 2154 to use the region's peculiar subspace phenomena to save his son, Quinn Erickson, who was trapped in a subspace bubble for 15 years. (ENT episode: "Daedalus")