The Heavenly Wall, also known as Zhanguerrie, is a highly fortified castle-settlement named after a series of large walls that divide it. It lies in the Mogxa of the Mogxan Empire. The fortifications and settlement was constructed this way in order to guard the Mogxan continent from invasion across one of the two land-bridges to Galae - the Ivory Road. It has been revitalised by the Sanitorium, which fears Crusader invasion.
Contrary to popular belief, none of the walls actually stretch completely from The Scar to The Rend - though one gets close. Their purpose is rather to funnel potential invaders into a number of terrains that are highly favourable to the defenders on the eastern side. There are 3 main tiers of walls, one of which cuts through what is now the core part of the city.
The other possible land route between Mogxa and Galae is north of The Scar. However, it is especially unstable, and leads into the difficult terrain of Cragrock and its Sanitorium ally Cragmoor. Consequently, the Crusaders have not seriously attempted to pass it, and instead hold out hope to get through the Grand Gate one day.