Qom is a city in the Central District of Qom County, Qom province, Iran, serving as capital of the province, the county, and the district. It is the seventh largest metropolis and also the seventh largest city in Iran. The city is 140 km to the south of Tehran, and on the banks of the Qom River. Qom is considered holy in Shi'a Islam, as it is the site of the shrine of Fatimah bint Musa, sister of Imam Ali ibn Musa Rida.