The Gargant's Graveyard is a vast array of sun-bleached bones found in the Ghurland Plains. Many of these bones are the remains of thousands of gargants but there are a substantial number of other skeletons as well including those of humans and orruks. Some of these ribcages and skulls are the size of duardin citadels. 
In the centre is the Big Skull, a massive skull named so by orruk. A vast, cracked and yellowing mountain above the surrounding plain which itself is littered with bones, spreading outwards like a grisly maze. Atop this is the Howling Labyrinth of Tzeentch built by the Daemoniac Conundrum - thousands of those that laboured to build it joined the boneyard around the great skull.
Orruk legend is that the skull had belonged to one of the monsters that Gorkamorka and the Hammer God had beaten to death in order to make the foundations for all the worlds. Daemons summoned by Zazul of the Radiant Veil told him that the skull was that of Agorath, a star-leviathan that swam in the void between realms. They claimed that the Daemoniac Conundrum had used Marrowcutter to slay the beast after a hunt lasting centuries.