the Hidden Land is another name for Osrakum, the land within the Sacred Wall of it crater
The Three Gates refers to the three gates that defend the Canyon entry into Osrakum; they are the primary defences of Osrakum
The Chosen refer to everything outside Osrakum as the ‘Outer World’
The high mountain wall of the crater of Osrakum is called by the Chosen the Sacred Wall. It separates their Hidden Land from the Outer World. The Sacred Wall is breached only in one place, by the Canyon of the Three Gates
The Cloaca is a channel cut into the rock floor of the Canyon of the Three Gates, allowing excess water in the Skymere, in Osrakum, to be drained out into the City at the Gates and, ultimately, the Gatemarsh
Osrakum is often referred to as “the Mountain”, particularly by the barbarians and the subject peoples of the Commonwealth
Osrakum is a theatre in which the Chosen play out their rituals of power. Display and grandeur are at the heart of these rituals and yet, except at the ceremony of the Rebirth that is held annually in the Plain of Thrones, these are rarely witnessed by their subjects. Their households bear constant witness to this pomp, but it is not they whom the Chosen have in mind as being their primary audience.