Bukhara (Uzbek Latin: Buxoro; Uzbek Cyrillic and Tajik: Бухоро; Russian: Бухара́) is one of the cities (viloyat) of Uzbekistan. Bukhara is a city-museum, with about 140 architectural monuments. The nation's fifth-largest city, it had a population as of 31 August 2016[update] of approximately 247,644. Humans have inhabited the region around Bukhara for at least five millennia, and the city has existed for half that time. The mother tongue of the majority of people of Bukhara is Tajik. Located on the Silk Road, the city has long served as a center of trade, scholarship, culture, and religion. UNESCO has listed the historic center of Bukhara (which contains numerous mosques and madrassas) as a World Heritage Site.