Holographic representation.

After imprisoning G'huun in the facility of Uldir, the titanic keepers of Zandalar built three grand seals in order to keep the Old God and its corruption locked away under Nazmir.[1][2]

These seals were built into the architecture of great pyramids spread out around the continent: one in Dazar'alor of Zuldazar, one in Atul'nazman of Nazmir and the last one in Atul'Aman of Vol'dun. All three pyramids face Uldir and at least two had roads running to the central facility at some point, but now each ends at the pit known as the Altar of Rot.

The seal in Atul'Aman was destroyed by Mythrax the Unraveler long ago,[3] while Atul'nazman was damaged by G'huun's minions. G'huun then ordered his blood trolls minions to attack the final one within Zuldazar.[4]