The Unicomplex was a vast Borg complex composed of thousands of connected structures and hubs spanning at least 600 kilometers, that housed hundreds of Borg ships and trillions of drones. (VOY: "Dark Frontier") It was considered, by the independent drones, to be the home of the Borg Queen. (VOY: "Unimatrix Zero") This complex is likely the closest thing that the Borg have ever had to a physical capital or headquarters.