- You may being looking for The Void, an anomaly with the same name.
The "Void" was the name given by the crew of the USS Voyager to a vast region in the Delta Quadrant where no star systems existed within 2,500 light years, and where all light from beyond was occluded from sensors by heavy concentrations of theta radiation.
The Void was created retroactively through temporal effects caused by thousands of years of interference by the Nacene. Originally, this region was filled with stars and included the Monorhan system, a linchpin of unstable space between the universe and the extradimensional Exosia. Following a civil war between Nacene factions, the Keeper of Light, an Ocampa-Nacene hybrid, used his powers to separate Exosia and heal the damaged space-time fabric. As a result, the entire area would be replaced by a starless void with its own, thousands of years of history. (VOY - String Theory novel: Evolution)
The Void was inhabited by at least one species, whose physiology had evolved to survive in complete darkness. In addition, a spatial vortex existed within the Void, which led to an area just outside the region. When Voyager entered the Void in 2375, they found themselves faced with a daunting two-year journey to cross it. The oppressive nothingness had an adverse effect on the morale of the crew, including Captain Kathryn Janeway, who secluded herself in her quarters, obsessing over her decision four years previously which stranded Voyager in the Delta Quadrant. The crew also found themselves with an abnormal amount of free time on their hands, leading to high demand for the holodecks, and inspired Ensign Harry Kim to compose a concerto on his clarinet titled, "Echoes of the Void."
After two months, the crew discovered that the Malon were using the vortex to dispose of antimatter waste, poisoning the indigenous species with theta radiation. To protect the aliens from the Malon, Captain Janeway conceived of a plan whereby a spread of photon torpedoes would be used to destroy the vortex. However, since the vortex could only be collapsed at the end which existed in the Void, where its dimensional radius was weakest, doing so would preclude the possibility of using the vortex to travel to the other side. Consequently, the crew modified their plan, deploying the torpedoes immediately upon entering the vortex. Reinforcing their aft shields to withstand the shock wave, the crew was able to safely navigate their way through the vortex, exiting beyond the boundary of the Void. (VOY episode: "Night")