Muṣaṣir (Assyrian cuneiform: KURMu-ṣa-ṣir and variants, including Mutsatsir, Akkadian for Exit of the Serpent/Snake), in Urartian Ardini 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 city's location is not known with certainty, although there are a number of hypotheses, all in the general area of 36°N 46°E / 36°N 46°E, in the Zagros south of Lake Urmia. François Thureau-Dangin tentatively located it at Mudjesir, 10 km west of Topzawa. Reza Heidari, an archaeologist of the "Cultural Heritage and Tourism Organization" of Iran's West Azarbaijan Province claims Rabat city near Sardasht, Iran as the location of Muṣaṣir.[1] H. F. B. Lynch claimed that it was close to the modern town of Rawandiz in Iraqi Kurdistan.[2]
Urartologist Paul Zimansky speculated that the Urartians (or at least the ruling family) may have emigrated northwest into the Lake Van region from Musasir.[3]