This mosque is one the largest and most secret mosques of Islamic world that the main core of it has been built on ancient foundation.
The main entrance of mosque has been located on eastern side. In this part there are small platforms on the right side of corridor related to Dayalemeh dynasty in fourth century. On the entrance left side of corridor there is a pillar related to Ale Mozafar in eighth century.
The most architectural changes in this mosque has happened in Seljuk era in fifth and sixth centuries. Among them we can point out to the verandas on two sides of open space and the domes of Nezamolmolk and Tajolmolk the two prime ministers of Seljuk era. on northern angle of mosque there is a big Veranda which is known as Sofeh Dervish (Dervish’s platform). Saheb’s mosque has been located on southern angle of open space on western angle of mosque’s open space is master’s Veranda and on eastern angle is student’s Veranda.
One of the most important parts of this mosque is Khajeh Nezamol Molk’s dome which is considered the most important part in magnificent and architectural delicacy. There is also an inscription in Kufic writing in upper part around the dome. In other part of mosque is also Tajolmolk’s dome. Although it is smaller than Nezamolmolk’s dome in width, however it’s unique in decorations artistically.
The collections of western chambers are the other beautiful parts of congregational mosque. Another architectural yard is Oljayto’s Altar which dates back to Illkhanan Mongol period. It was built by the great architect “Heidar Isfahani” and by the order of oljoyto and his prime minister “Mohammad Savajei”
There is a vast chamber on the west of western veranda and Oljayto’s Alter which has been built a little lower than collection of Oljayto’s Alter and it’s belonged to the period of “Bye Sanghar Taymoori” reign (in 851A.D). this chamber is named winter chamber for its unique architectural structure. According to inspections, it seems that there have been some changes at Safavid time. A platform with the name of “Hakim” has been annexed to the collection of mosque’s building that shows the year 996A.D on the inscription. the architectural changes generally described below:
– the created buildings in the first period of Seljuk era in fifth century.
– the created buildings in the second period of Seljuk era in sixth century.
– the annexations of Illkhanan Mongol period.
– the annexation of Ale Mozafar period.
– the annexed building in ninth century.
The annexed building in eleventh century.
This mosque includes numerous entrance doors in which each one has found different name.
Today this mosque is a various encyclopedia of architecture and internal ornamental arts which results in efforts of Iranian architect and artists.