With expansion of Islam in Iran, the tombs of Imams(descendants of Islam prophet and religious leaders in S hiite) were gradually changed to places of pilgrimage and shrines. Subsequently, people and religius leaders constructed suitable and outstanding buildings or Imamzadehs which have unique architectural styles .
The most famous artists of the time, with making use of existing possibilities, portrayed their skills, arts and genius in construction and ornament of these places . these genius and talents are reflected in most of such buildings .
The places of pilgrimage in Iran are divided into two categories :
1. The places with international fame like the sacred Shrine of His Holiness Imam Reza in Mashhad City and the Shrine of Her Holiness Masoomeh in Qom. The social and economic life of these two cities is interlocked with the existence of these shrines.
2. 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-Moosa famous as shah Cheraq in shiraz; the shrine of his Holiness Abdol-Azim in Shahr Ray (south of Tehran city); and Mausoleum of Danial Nabi in Susa (Shoosh).
These tombs, mostly dome-shaped, are places of pilgrimage for local people, especially at the week-ends .On the other hand, since some of these places are located in regions with a pleasant climate, they are also placees for recreation surrounded by different shops and other services.So, many of Imamzadehs are located in the centers of cities.
In dition to Siites, there live in Iran other religious minorities like Sunnites, Zoroastrians, Assyrians, Armenians, and Jewish who have their own sacred religious places.Here some of these places, which are important from tourism point of view, are pointed out:
The most important pilrimage placec of Sunnites are Mausoleum of Sheik-e-Jam in Khorasan and Sanandaj jame Mosque.
Zoroastrians of Iran, who mostly live in Yazd and Tehran, annually go to Persepolis, Naghsh-Rostam, Tagh Bostan and Bistoon for their religious ceremonies and rituals. The old Azargoshasb fire-temple in Takht-e-Solayman, Kashmar Tower in Khorasan, and Orumyeh Lake are other sacred places of Zoroastrians.
Armenians travel to Tatawoos Church in Siah Cheshmeh closed to Makoo, in summers for pilgrimage.In addition to 13 churches in Jolfa (Isfahan city), 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 Azarbaijan (of which the most beautiful is St.Stephan church), Salmas, and Makoo.
The most important place of pilgrimage of the Jews is the tomb of Ester and Mardkhay in Hamedan.