Mountains are of high importance in Iran due to the particular geography of this land. In addition to being ecologically significant, mountains offer multiple functions for Iranians that makes these natural elements to have different meanings for people to the point that most of the mountains adjoining residential areas have special names. In this regard, this research tries to study Alborz Mountains as the most important historically and ecologically mountains in Iran where Tehran, the most populated city and the capital of Iran, is located. Research in this area shows that the function of Alborz Mountains have changed for the people over time or have declined to a lower status. These mountains do not have their previous position in the minds of the people, and the authors believe that Iranians used to be consider Alborz Mountains as a cultural element with objective and subjective aspects. Therefore, the purpose of this paper is to investigate the functions of Alborz Mountains and to study the relationship between mountains and people over time in order to find the meaning of the Alborz Mountains in terms of documentary and historical studies. The results of the research show that based on the conceptual scope of the landscape approach (which is a holistic and objective-minded approach to nature), the city and the mountains in general are not the main reasons for negligence of Alborz Mountains in the minds of people. In addition, the mountains for the people of Tehran, who are the main inhabitants of Alborz Mountains, are no longer a cultural landscape element with objective and subjective aspects. The objective aspects of mountains have been gradually disappeared or decreased considerably due to the loss of their objective functions and these elements have been eventually transformed into subjective elements.