Muṣaṣir (Armenian: Մուծածիր, Assyrian KURMu-ṣa-ṣir and variants, including Mutsatsir, Akkadian for Exit of the Serpent/Snake ), in UrartianArdini (likely from ArmenianArtin) was an ancient city of Urartu, attested in Assyrian sources of the 9th and 8th centuries BC.
It was acquired by the Urartian King Ishpuini ca. 800 BC (see the Kelashin Stele). The city's tutelary deity was dḪaldi. The name Musasir in Akkadian means exit of the serpent.