Mountains have played an essential role for humans since ancient times and since the formation of early civilizations. But this importance was more in Iran's land because of Iran's geographical location and its proximity to the Tropic of Cancer; if it were not for the mountains, this land would be a vast desert. In addition, the many physical and objective functions of the mountain for the Iranians had caused the mountains to have mental value to the Iranians, and a mental relationship had been formed between them and the mountains. But with, the passage of time and events such as the appearance of religions, modernity, and postmodern concepts caused the mountains to lose their objective and mental functions over time. As a result, this relationship has reached a point where The Alborz Mountain (one of Iran's most important mountains, which had particular importance in the construction of Iran's history and geography) have no place in the collective life of Tehran.

Therefore, the main issue of this thesis is the lack of a strong relationship between Tehran today and the Alborz Mountain. Therefore, this thesis put two main questions in its plan to examine the issue: 1- Why, in the present era, has the historical and strong relationship between "people and mountains" in Iranian culture weakened? 2- What are the reasons for removing the mountain from the current landscape of the city of Tehran today? To answer these questions, it was necessary to conduct multidimensional studies in a phenomenological paradigm to thoroughly examine the Alborz Mountain' existence in Tehran's current collective life, which was forgotten among religious, historical, worldview changes, and technological possibilities.

Thesis studies are scrutinized in five chapters, which in several separate but parallel studies, different dimensions of the proportion of people and settlements in the foothills of Alborz. The first chapter contains two studies and, with the method of studying documents, examines theories of conflict between humans and the environment, various approaches to the relationship between man and the environment, the importance of mountains in human life, and the types of relationships between man and mountain.Since Iranians had a holistic view of the mountain, in this thesis, the landscape approach is an academic concept that has a holistic approach similar to Iranians in the past; the second chapter deals with the concept of landscape and landscape approach by studying the documents. In the third chapter, the types of relations between Iranians and mountains up to the contemporary period are examined. Since in the period of tradition, the functions and meanings of mountains in Iran have led to the production of religious identity for it, the sanctity of mountains and its relationship with other natural elements have discussed. In the fourth chapter, the course of changes in the meanings of Alborz Mountain for Tehran is examined. In the following, Iranian literature has been studied to study the evolution of the meaning of the mountain. In the fifth chapter, the first, Tehran city issues related to mountains are studied in four studies. Second, the events that caused the undesirable relationship between Tehran and Alborz are identified by thematic analysis by experts. The third study is to study the meanings of the Alb