Zanjan probably dates back to the Sassanid period. Conquered by the Muslims in the 7th century, obliterated by the Mongols and by Tamerlane in the 13 th and 14 th centuries, and having a vivid record in civilization, culture, arts and sciences, Zanjan has experienced both glory and hardship. The city is know for the Zanjan upheaval, resulting in what was by far the largest of the battles between the members of the Bahai movement and Persian troops during the late 1840s and early 1850s, involving perhaps three thousand Bahais and thirty thousand government troops and irregulars. Prior to the Iranian Revolution, the city witnessed fighting between the local people and the Iranian army in 1978. The city is the centre of an agricultural zone with abundant grain harvests.
Industries produce milled rice and flour, hand-woven cloth, metal ware, and coarse carpets.
The Caravanserai Sangi - the ancient inn for caravans travelling from Asia to Europe, built in the 16th century, during the Safavid dynasty, is the oldest building in Zanzan city. During recent times it has fallen into disrepair, and it's current appearance doesn't make justice to its former glories. Mosque - The Mosque and adjoining Islamic school date from the Qajar period. The building has delicate and intricate decoration in tilework, providing an exceptional visual effect, and the architecture with tall arches and ample verandas make it most elegant. It's located in the centre of the old town.