Legion

During the war against the undead, the great desert where Pezerx now stand was a territory fully controlled by the repugnant corpses, many explorers and adventurers, in search of riches are sorely reminded of this fact when they uncover one and attempt to break inside, only to be met by a swarm of dried corpses and skeletons, pouring out of the ruins like a tidal wave, slaughtering them all, taking them apart and dragging their bodies through the sand, back inside.

The ruins are sealed once more, and the desert, as if well aware of the horrors dwelling inside, covers it once more, burying the hateful dead once more, until someone else made the dire mistake and it all repeated.