TUN, a town in the province of Khorasan, Persia, situated about 150 m. S. of Nishapur in 34° N., 58° 7' E., at an elevation of 1200 ft. The town, which has a population of 7000, is surrounded by a wall, 20 ft. in height, raised on a high rampart of mud. It has three gates, handsome bazaars, good caravanserais and numerous large gardens and fields producing opium, tobacco and cotton. Some silk is also grown.