The Great Worms are gigantic creatures that dwell in the Amber Steppes of Ghur. They come from the caverns beneath the Steppes and in the Age of Myth they were driven out of those depths by great rains.
They crawl ceaselessly across the Steppes, devouring everything in its way. People of Ghur have made their way on to the back of the worms and over time raised cities and bastions there..
Some steppe clans known as Vurm-tai nomads – worm-riders took to following the migration routes of the great worms and picking over what was left in their wake, or raiding the caravans that travelled to and from the worm-cities.
- Shu'gohl: Known as the Crawling City.
- Guh'hath: Known as the Brass Bastion and was populated by Khorne Bloodbound  until the Realmgate Wars when it was cleansed of Chaos by Stormcast Eternals. It still bore ancient wounds, runes carved by the efforts of thousands of slaves into its hide boasting of the glory of Khorne, but they had begun to heal and fade.
- Rhu'goss: Known as the Squirming Citadel it was occupied by the Tzeentchian sorcerer-king Terpischore the Unwritten and his crystal automatons until the Realmgate Wars when it was cleansed of Chaos by Stormcast Eternals.