The al-Nabi Mosque is a famous mosque in Qazv?n . The mosque has an area of about 14,000 m² , and bears inscriptions indicating that Fath Ali Shah of the Qajar dynasty was the founder of the mosque . Other sources however indicate that the mosque has been in existence since the Safavid period . It is now believed that the architect of the structure was Ustad Mirza Shirazi with the date of construction being 1787 .
Its double layered dome measures 15m in inner-diameter , with the top of the inner layer positioned at 20.83m above ground level , while the external apex is 23.25m high .
There was formerly an elevated minaret flanking the dome , of which the French explorer Madame Jane Dieulafoy had written . The mosque has four iwans in its courtyard .
The portal contains an inscription in nastaliq calligraphy dated 1787 CE . Similar to Qazvin's Masjed e Jame (Congregation Mosque) , this mosque has a shabestan that is now used as a library .