The hills that bisect Caorpu'tzor are so built-up with fortifications that they no longer look like hills, but a continuous wall with towers and strong points. This hill wall is ten miles long and called the Inur Guld. It was built to serve as a barrier to the dinosaurs, demons and other foes that run amok in the plains north and south of them. The Mezrack fortified this area so as to have a communication artery between their holds in the hills and low mountains east and west. After a time, they built an Underdark link, a hundred feet down from the wall which is more secure than that of the surface.
A road cuts along the top of this wall, across bridges, and sometimes through the walls and towers of Inur Guld. The enclosed areas of the road were made for the safety of merchants when the place is under attack. These attacks could be a ground attack by raiding humanoids or an attack from a dinosaur. The most dangerous though are those from above by flying dinosaurs like the pterodactyl. The walls were made thick to handle demons seemingly created to serve as living siege engines. Demon attacks are rare, but growing more common, with Demogorgon finding ways to get his forces out of Turgon.