Chehel Sotoun (Alighapou Palace Museum), a Safavid pavilion is located amid the gardens in the central square of the old city (Qazvin). It is the only remaining palace of the palace complex during Tahmasp dynasty.
Two-storey octagonal building was built on 500 square meters. The building was constructed with brick columns and arches in the semi-circular.
The palace was used as historical treasures and ancient objects in 1958 and now has been become as an important calligraphy museum in Qazvin.