Shiraz is the fifth-most-populous city of Iran and the capital of Fars Province, which is also known as Pars and Persis. At the 2016 census, the population of the city was 1,565,572 and its built-up area with Sadra was home to almost 1,800,000 inhabitants. Shiraz is located in the southwest of Iran on the “Rudkhaneye Khoshk” (The Dry River) seasonal river. It has a moderate climate and has been a regional trade center for over a thousand years. Shiraz is one of the oldest cities of ancient Persia.