Khomaini Shahr city is one of the historical cities of the province which its antiquity dates back to Sassanides era. It is said that, Kohandezh (old castle), which is located on the way to Isfahan, has been the capital of Sassanides. Atashgah (fire-temple) mountain, Menar Jonban (shaking minaret), and Jame’ mosque of Khazan are among other historical monuments of the region. The old name of Khomaini shah was "Sedeh", which was changed to Homayoun Shahr in Pahlavi period and after Islamic Revolution in 1979, it was named khomaini shahr.