FIRUZKUH, a small province of Persia, with a population of about 5,000. Its chief place is a village of the same name situ ated in a valley of the Elburz, about 90 m. E. of Teheran, at an elevation of over 5,000 ft. and in 3 5 ° 45' N. and 5 2 ° 3o' E. It has a population of 2,500. A cliff on the eastern side of the valley is surmounted by the ruins of an ancient fort popularly ascribed to Alexander the Great.