In 2003, Abbas William Samii estimated that there are 90 000 (media observers) to 300 000 (European sources) clerics in Iran, with, back then, 40 000 students at the religious seminaries. To this he add 60 000 "people with no formal training or qualifications who acted as urban preachers, rural prayer leaders, and procession organizers." As for the numbers of seminaries, Qom alone had 60. Another major religious institution in Iran is the shrine. Pilgrimage to the shrines of imams is a specific Shia custom, undertaken because Shia pilgrims believe that the imams and their relatives have the power to intercede with God on behalf of petitioners. Of the more than 1,100 shrines in Iran, the most important are those for the Eighth Imam, Ali al-Ridha, in Mashhad and for his sister Fatimah bint Musa in Qom, and for Seyyed Rouhollah Khomeini in Tehran. Each of these is a huge complex that includes the mausoleum of the venerated one, tombs of various notables, mosques, madrassas, and libraries. Imam Reza's shrine is considered the holiest. In addition to the usual shrine accoutrements, it comprises hospitals, dispensaries, a museum, and several mosques located in a series of courtyards surrounding the imam's tomb. The shrine's endowments and gifts are the largest of all religious institutions in the country. Although there are no special times for visiting this or other shrines, it is customary for pilgrimage traffic to be heaviest during Shia holy periods. Visitors represent all socioeconomic levels. Whereas piety is a motivation for many, others come to seek the spiritual grace or general good fortune that a visit to the shrine is believed to ensure. Since the nineteenth century, it has been customary among the bazaar class and members of the lower classes to recognize those who have made a pilgrimage to Mashhad by prefixing their names with the title mashti. Shrine authorities have estimated that at least 4 million pilgrims visit the shrine annually in the early 2000s. There are also important secondary shrines for other relatives of the Eighth Imam in Tehran and Shiraz. In virtually all towns and in many villages, there are numerous lesser shrines, known as imamzadehs, that commemorate descendants of the imams who are reputed to have led saintly lives. In Iraq the shrines at Karbala and An Najaf also are revered by Iranian Shias. Pilgrimages to these shrines and the hundreds of local mamzadehs are