Jameh Mosque of Nain is one of the oldest mosques in Iran and its construction date is not exactly clear. Some people attribute it to Omar Ibn Abdolaziz caliphate time. Professor Pope attributes the mosque building to 350 hijri year and French Andre Godard attributes it to Deilami era. The mosque is located in the old neighborhood in Nain City and Pirnia and Narin Castle (Narenj Castle) are around it. It dates back to the per-Islamic period, about Arsacid and Sassanid eras and no more than a sand hill is left of it at the moment.