Kir of Moab is mentioned in the Hebrew Bible as one of the two main strongholds of Moab, the other being Ar. It is probably the same as the city called Kir-haresh, Kir-hareseth (Hebrew: קִיר-חֲרֶשֶׂת; Isa 16:7), and Kir-heres (Hebrew: קִיר חָרֶשׂ; Isa 16:11; Jer 48:31, 48:36). The word Kir alludes to a wall or fortress. It is identified with the later city Al Karak.
According to the Books of Kings, after the death of Ahab of Israel, Mesha, the king of Moab (see Mesha Stele), threw off allegiance to the king of Israel, and fought successfully for the independence of his kingdom. After this Jehoram of Israel, in seeking to regain his supremacy over Moab, entered into an alliance with Jehoshaphat, king of Judah, and with the king of Edom. The three kings lead their armies against Mesha, who was driven back to seek refuge in Kir-haraseth. The Moabites were driven to despair. Mesha then took his eldest son, who would have reigned in his stead, and sacrificed him as a burnt-offering on the wall of the fortress in the sight of the allied armies. “There was great indignation against Israel: and they departed from him, and returned to their own land.” The invaders evacuated the land of Moab, and Mesha achieved the independence of his country.(2Kings 3:20-3:27)
The Bible notes elsewhere that this is the place to which Tiglath-pileser carried the captives after he had taken the city of Damascus (2 Kings 16:9; Amos 1:5; 9:7). Isaiah 22:6 mentions it along with Elam. Some have supposed that Kir is a variant of Cush (Susiana), on the south of Elam.