The Grand Mosque of Isfahan, also known as the Old Grand Mosque and the Friday Mosque of Isfahan, is one of the historical monuments of Isfahan in Iran, dating back to the second century AH. The Grand Mosque of Isfahan uses different styles of Iranian architecture, and of course, architecture from neighboring countries can also be found in it. Two-section, three-section, and four-section brick columns, brick lintels, fountain arches, quadruple porches, double doorways, each for a passage, and different decorations in each part of the mosque and new innovative methods are considered its important components. The first mosque design was a Shabestani mosque, which was built in the Arabic or Khorasani mosque style. In the fifth century AH, the architecture of the mosque changed, and the previous Shabestani mosque was converted into a four-bayan mosque. Mosques built in the new four-bayan style are called "Iranian mosques"