Zanjan, city in northwestern Iran, located on the Zanjan River near the Caspian Sea in Zanjan province, of which it is the capital. Sitting in a valley of the Zagros Mountains, Zanjan is a manufacturing and trade center. Its chief industries include refined zinc, metalware, cutlery, cooperware (wooden barrels and tubs), textiles, flour, milled rice, processed foods, carpets, cement, and bricks. Zanjan is on the main highway and railroad linking Tehran to the east with Tabriz to the northwest. A road south to Bijar connects the city to Kurdistan. The area is home to the early-14th-century mausoleum for the Mongol ruler Oljaitu, which is situated in the village of Soltaniyeh, 26 km (16 mi) southeast of Zanjan. The tomb's dome, 52 m (171 ft) high, is the largest dome in the Middle East.
Because Zanjan sits at the foot of the mountains that separate Azerbaijan from the central plateau, it had developed as a caravan stop by the time of the Sassanid Empire (AD 224-651). It was devastated by the Mongols in the early 13th century and did not recover its prosperity until the Safavid dynasty (1502-1722). In the mid-19th century, Zanjan became a center of the young Baha'i religious movement and was partially destroyed in 1850 when government troops captured the town to suppress the Baha'is. By the beginning of the 20th century Zanjan once again was a prosperous commercial center. Major industrial projects began in the 1960s and spurred migration to Zanjan. As a result, the city's population has increased more than fourfold since 1966. Population (1996) 286,295.
