The Briar Patch, known to Klingons as Klach D'kel Brakt, was a region in Sector 441, in the Beta Quadrant. This region was known for containing dangerous space matter, including the remains of supernovae, false vacuum fluctuations, metaphasic radiation, and at least two habitable planets, one of which was settled by the Ba'ku. Ships in the vicinity had to travel at less than one-third impulse power to avoid overheating the vessel's impulse manifolds. The colloquial "Briar Patch" name used in the Federation was first coined by criminal geneticist Arik Soong in the 22nd century, a reference to the Br'er Rabbit of the 1880s Uncle Remus stories written by Joel Chandler Harris of Earth.
In 2256, the region's location was labeled on a tactical map on the bridge of the USS Discovery. (DIS: "Choose Your Pain")
Later that year, this region's location was labeled on the star chart "Alpha/Beta Quadrant Overview" in the ready room aboard the USS Discovery. (DIS: "Magic to Make the Sanest Man Go Mad")
In 2271, the region was the site of the celebrated Battle of Klach D'kel Brakt, where Dahar Master Kor led the Klingon Empire in a glorious victory over the Romulan Star Empire. Nearly a century later, Kor was still fond of re-playing the battle in holosuites. (DS9: "Blood Oath")
By the 24th century, the region was part of Federation space.
http://memory-alpha.wikia.com/wiki/Briar_Patch