CASBIN, Kasvin, Kazbin, a city of Persia, in the province of Irak, in 36° 12' N. lat. and 49° 53' E. long., and 108 miles W.N.W. of Teheran. It is built in a fertile plain, south of Mount Elburz, and is square in form, and surrounded by a wall of brick, with towers. Its extent is greater than that of Teheran; but the place has been repeatedly shaken by earthquakes, and many of the streets are in ruins, as are most of the magnificent buildings seen here by Chardin in 1674. The most remarkable remains are the palace of the Sufi princes, and the mosque, with its large dome. The city is said to have been, founded in the 4th century. In the 16th century Shah Tamasp made it the capital; and it remained so till Shah Abbas the Great transferred the seat of government to Ispahan. The town still bears the name of Dar-el-Sultanet, or the “seat of royalty.” The dust and heat of the place are very oppressive; it is furnished, however, with baths, and with cisterns fed by underground canals. The system of irrigation formerly carried on by these canals or kanauts rendered the Plain of Casbin one of the most productive regions of Persia. They are now mostly choked up, except in the immediate vicinity of the city. The manufactures of Casbin are velvet, brocades, carpets, a kind of coarse cotton-cloth termed kerbas, and sword-blades. The trade of the city is still considerable; great quantities of rice, and of silk for Baghdad and India, are brought to it from the Caspian provinces; and the bazaars are large. Casbin is also of some military importance, lying as it does at the entrance of the defile which leads into Ghilan. It is the birthplace of the poet Lokman, and of the geographer Ham el Oullah. Population in 1868 estimated at 25,000.