The Hypercube station was a large starbase facility used by the Borg Collective. The station resembled a single large cube with six smaller cubes attached to its various sides. A unique factor of the facility was that it was suspended in Transwarp and somehow maintained the Borg's Transwarp conduits. This station was constructed in a Thorne subset of eleven-dimensional transpace.
A Borg cube that collected an assimilated colony on New Titan and had been secretly infiltrated by Captain Jean-Luc Picard and Doctor Beverly Crusher docked with the Hypercube station thus allowing the Federation to become aware of its existence in 2371. Ambassador Spock was also captured and transported to this facility for assimilation by Speaker of the Borg Collective Vox. (TOS novel: The Return)