Tiragarde Keep is Alliance castle on the east coast of Durotar.
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Tiragarde Keep, Durotar

It was created by Admiral Proudmoore of Kul Tiras when he landed in the Orcs homeland with a fleet of ships which broke a treaty between the Horde and the Alliance. This resulted in Admiral Proudmoore being slain by Orcs . After this Kul Tiras sailor remained until they were killed during the cataclysm. However Allaince soldiers from Northwatch Hold in the Southern Barrens then arrived to stop the keep falling to the Horde.