The Beta Marada system was a star system in the Alpha or Beta Quadrant, beyond the boundaries of the United Federation of Planets. It was believed to have once been inhabited by a race called the Darzun.
In 2367, the deep space explorer USS Marco Polo entered the Beta Marada system, and was attacked by four unidentified defensive vessels, later theorized to be automated Darzun ships left behind after that race disappeared from the sector. The USS Enterprise-D responded to the Marco Polo's distress call, and Commander William T. Riker was able to destroy the defense drones by drawing them into a high-gravity anomaly near the Beta Marada system. (TNG comic: "Thin Ice")