Qazvin is one of the most important historical cities of Iran. Its construction and prosperity have been attributed to Sassanid Dynasty. The archaeological excavations in Qazvin plain, however, date back to the 7th millennium BCE. In the Islamic Era, Qazvin was introduced as one of the country's scientific centers and its prosperity doubled. Water resources in Qazvin has created many reservoirs, Qazvin is called the city of treasure trove.