Which mosque in Isfahan is famous for establishing the four-iwan plan as a major Iranian mosque layout?

The Jameh Mosque of Isfahan is famous for establishing the four-iwan plan as a major Iranian mosque layout.

The mosque developed over many centuries on the site of earlier religious buildings. Its present architectural character was shaped particularly during the Seljuk period, when four monumental iwans were arranged around a central courtyard.

An iwan is a vaulted hall or space open on one side to a courtyard. The four-iwan arrangement became a defining pattern in Iranian mosque architecture and was later used in religious schools, caravanserais, and other monumental complexes.

The Jameh Mosque also preserves major structural innovations, including Seljuk domes and later Timurid, Ilkhanid, and Safavid decoration. Its long development makes it different from a mosque built in a single campaign, and its layers provide a record of changing Iranian architectural techniques.