Iran is the birthplace of Zoroaster, the founder of the Zoroastrian religion one of the oldest religions of the world. The official religion of Iran, based on Article 12 of the Constitution, is Islam (Shiite), and about 99.56% of the people of the country are Muslim. Disciples of other branches of Islam such as Hanafi, Maleki, Shafei, Hanbali, and Zaidi in Iran are highly respected and live freely without any limitations. In the Constitution of the Islamic Republic of Iran, religions such as Zoroastrian, Christian, and Judaism are officially recognized and their disciples have equal political, social and economical rights as Muslims. Religious minorities of Zoroastrian, Armenian, Jew, Assyrian, and Chaldean have their own independent representatives in the Islamic Consultative Assembly (Parliament).
With the expansion of Islam in Iran, the tombs of the Imams (descendants of the Prophet of Islam and Shiite religious leaders) were gradually changed to places of pilgrimage and shrines. Subsequently, people and religious leaders constructed suitable and outstanding buildings in these places. These buildings or Imamzadehs have unique architectural styles. The most famous artists of the time, making use of existing possibilities, portrayed their skill, art and genius in the construction and ornamentation of these shrines. Genius and talent are reflected in most such buildings. The places of pilgrimage in Iran are divided into two categories:
The places with international fame like the sacred Shrine of His Holiness Imam Reza (PBUH) in Mashad and the Shrine of Her Holiness Hazrat Ma'soomeh (PBUH) in Qom. The social and economic life of these two cities is interlocked with the existence of these shrines.
The places with local and regional fame. These places of pilgrimage are scattered in different parts of the country of which the most important ones are: the Shrine of His Holiness Ahmad-ebne Musa (PBUH) famous as Shah Cheraq in Shiraz, the Shrine of His Holiness Hazrat Abdol Azim in Shahr Ray (south of Tehran); and Mausoleum of Danial-e-Nabi in Susa (Shoosh)
These tombs, mostly dome-shaped, are places of pilgrimage for local people, specially on weekends. On the other hand, since some of these places are located in regions with a pleasant climate, they are also places for recreation surrounded by different shops and other services. So, many Imamzadehs are located in the suburbs of cities and villages.
In addition to Shiites, there live in Iran other religious minorities-Sunnites, Zoroastrians, Assyrians, Armenians, and Jews who have their own sacred religious places. Here some of these places, which are important from a tourism point of view, are pointed out:
Armenians travel to St. Tatavoos Church, located in Siyah Cheshmeh close to Maku, in summers for pilgrimage. In addition to 13 churches in Jolfa (Esfahan), which are sacred places for Armenians, many other historical churches in other parts of the country may be pointed out like many old churches in Azarbayjan (of which the most beautiful is St. Stepanous Church), Salmas, and Maku.
The most important place of pilgrimage for Jews is the tomb of Esteroo Mord Khay in Hamadan.
Religious 
The places with international fame like the sacred Shrine of His Holiness 
