Isfahan Jame mosque
It is an Islamic architectural musuem through 800 years. It is Iran’s biggest mosque. In sasanid era it was a worship place and later in seljuk time became a mosque. In 12 century there was ignition and renwed in 1121. The best brick dome in Iran was made then that lasted more than 900 years. It really is an architectural marvel, there are interesting tile and ston works, sun dial ston , plaster work, small intentional imperfections, miniature paintings. Eventually you can follow the evolution of Islamic architecture in the last millennium. Also the diversity and quality of the vaults are attractive.