Jago is an ancient, almost lifeless Fortress World located in a group of star systems that form the Sabbat Worlds Sector along the rimward edge of the Imperium of Man's Segmentum Pacificus. The terrain of Jago is mostly flat desert with massive mountain ranges dividing the planet. Partially-filled trenches, covered by the dust of millennia of sandstorms, dot the landscape.
Unknown hands also built massive barracks, fortifications, pillboxes and trenches which tower far above and below the surface of the planet. The identity of the builders are unknown, as these structures are far too large to have been built by humans or any other known xenos species.
Sabbat Worlds Crusade
Jago was the site of a covert Imperial military insertion to battle the Forces of Chaos, mostly Blood Pact Legions, during the Sabbat Worlds Crusade. Specifically, Colonel-Commissar Ibram Gaunt and his Tanith First-and-Only ("Gaunt's Ghosts") were charged with covering the flank of Lord General Barthol Van Voytz's task force by capturing and defending the ancient fortress known as the Hinzerhaus, which was built on the side of a mountain long before the dawn of the human species. During the subsequent battle, nearly half the Tanith regiment was lost, and Colonel-Commissar Gaunt was mistakenly deemed killed in action as well.
- Only in Death (Novel) by Dan Abnett