Nain, in Isfahan Province, Iran is home to some of the most outstanding monuments in Iran. The city is known for the underground aqueducts (qanat in Persian) which were built more than 3,000 years ago and still function today. Nain is also home to the Jame Mosque, which is one of the oldest mosques in Iran, dating to the 8th century CE. It is believed that the basement of the mosque was used as a fire temple before the coming of Islam. The minaret, which stands at 28m, was added only 700 years ago.
Rigareh water mill, based on the qanat system is well preserved, though the its date of construction is unknown. At Rigareh, it is possible to climb into the functioning Keykhosrow qanat.
Other local monuments include the impressive Mosallah edicice, which houses the mausoleum of Emamzadeh Sulta Seyyed Ali, and was used as a pilgrimage site for visitors. The garden contains a water reservoir which remained in use until the modern day. Narin castle, a pre-islamic construction also lies nearby. Both its age and use are disputed, but it is believed that the castle was used as a military base.