Interrogation was a specially crafted location on Alliance vessels, designed to be isolated from the rest of the vessel for the purpose of separating a single Borg drone from the Borg Collective.
In 2294, Supreme Arbiter of the Alliance Sarek had the Wisdom's commanding officer transport James T. Kirk and Montgomery Scott to Interrogation until he could determine they were not spies of the Borg. Later, Sarek had the Cardassian Zarcot transported to Interrogation after the former Councilman attempted to have him assassinated through deception. (Star Trek novel: Engines of Destiny)