The Clutch was a nomadic space fleet.
The Galyari were at the center, but hundreds of other species had ships surrounding them. The Sixth Doctor and Evelyn Smythe visited it in the 27th century, (AUDIO: The Sandman) as did Bernice Summerfield separately while she was trying to retrieve the Wishing Bone of Perlor. (AUDIO: The Bone of Contention)