Construction of the 1394 km trans-Iranian railway began in 1927 and was completed in 1938. The Trans-Iranian Railway was the result of a successful collaboration between the then Iranian government and 43 contractors and companies from different countries. According to #UNESCO, the project has had its own difficulties, especially in the mountainous areas and the engineering behind it is complex and considerable. There are 174 large bridges, 186 small bridges and 224 tunnels in Trans-Iranian Railway, and the government of Iran completed the project through tax revenues instead of borrowing or handing over control of the project to foreigners. This railway, which connects the Caspian Sea in the north of the Iranian plateau to the southwestern regions of the country in the Persian Gulf, passes through two large mountainous regions and crosses bridges, rivers, hills, forests, and plains. There are four different climates along the Iranian railway and in addition to the technique and quality of construction, it is prominent in the world in terms of its tourism potentials and its natural landscapes and attractions.
An important part of the Trans-Iranian Railway is located in the province of #Mazandaran which is known as the Northern Railway. In terms of climatic conditions, this railway is divided into plains and mountains; the highest point of this railway is in Gaduk mount with an altitude of 2112 meters above sea level. The northern I passes from Gorgan to Shirgah along the green plains and then enters Gaduk mount and Firuzkuh after leaving behind Savadkuh forest and mountainous areas. Savadkuh Railway has beautiful views such as the railway crossing through the heart of the forest near the Telar River, Veresk Bridge, and Doab Kalantari Rail Bridge.
Image: Doab Kalantari Rail Bridge