Interspatial manifolds
An interspatial manifold was used to support the structure of a transwarp hub.
Interspatial manifolds were protected by force fields, which were controlled by the Borg Queen and were essential for the operation of a transwarp hub.
If one of the manifolds was destroyed, the hub could still function. If enough of them could be destroyed simultaneously, a cascade reaction would occur which would then lead to the destruction of the transwarp hub. (VOY: "Endgame")