Iranian traditional architecture is one of the world's architectures par excellence. It was one of the most important architectures in the medieval Islamic world. Iranian architecture has developed over millennia in response to its religion. Many traditional and vernacular buildings in Iran show that the architects had been so clever in harmonizing the Iranian religion and architecture in the past. The architects know how to adapt architecture to Iran's conditions. From 1900 to now, thousands of new homes, apartment units and buildings have been constructed in Iran. In particular, the Iranian cities have expanded enormously and their great old structures are complemented by massive new urban developments. Learning from traditional architecture always can help us to take lessons on the Iranian beliefs directly from the past without extra expenditure.

This article will explain the impacts of Iranian religions (Zoroastrian and Islam) on its architecture, and the major focus of the paper is to introduce how Iranian architecture has been influenced by the religion. It will analyze the Iranian architecture in the past and will show how the Iranian architecture was in harmony with Iranian religion, as well as its ideology. Then it will demonstrate in detail how its new planning solutions have failed to continue the thoughts of the past.

Moreover, to better understand the role and relations of architecture and identity, this paper attempts to discover the changes of Iranian architecture through the last century. The results provide an effective strategy for future planning of Iranian cities.

To accomplish this purpose, this paper is organized as follows: after the introductory part, the Iranian architecture is introduced in Section II, followed by the explanation of the changes of its architecture in section III. Study results are presented in Section IV and finally the conclusions will be addressed in section V.