The story of Orgrimmar.
Orgrimmar is the capital of the Horde, a fortress city of red stone, iron and spiked timber built into the canyons of northern Durotar. Thrall founded it shortly after the Battle of Mount Hyjal, when the orcs he had freed from the internment camps finally had a land of their own, and he named it for Orgrim Doomhammer, the old Warchief who had been his friend and mentor. Goblins, tauren, Darkspear trolls and the half-ogre Rexxar all lent their hands to building it.
The city reflects the new Horde Thrall set out to make. Orcs fill its streets, but the tauren have the Valley of Wisdom and the Darkspear the Valley of Spirits, and the Forsaken are arriving in growing numbers. Shamans teach the old ways that the orcs lost under the warlocks' rule, and warriors test themselves in the training grounds. Thrall himself rules from Grommash Hold, named for Grom Hellscream, who killed the demon Mannoroth and freed the orcs from their blood curse.
Not every orc has left the old ways behind. Beneath the city, in the Cleft of Shadow, warlocks still keep their guild, and the tunnels below lead down into Ragefire Chasm, where cultists of the Shadow Council and the Burning Blade plot against the Warchief in the city's own foundations.
Written for this site from the game's lore. Further reading: Orgrimmar on Warcraft Wiki.

