Borg Transwarp Hub
From FEInfobase
A transwarp hub was a structure used by the Borg pre war to connect their network of transwarp conduits making them easily accessable.
The transwarp conduits made travel at speeds greater than warp 9.998.The transwarp hubs were one of the borgs greatest assets during the war.Fortunatly most of them were destroyed before the end of the war.It is unknown if any stable hubs still exist or if the conduit system is still viable for travel at all.