Semnan is one of the cities of Iran and the center of Semnan province and Semnan county. This city is located in the south of Alborz mountains and north of Dashte Kavir on the route from Tehran to Khorasan. Its climate is dry and temperate. Areas such as Dashte Kavir, Rige Jenn and Tepe Hissar are of the most important geographical features in the south of Semnan. The seasonal Golrudbar river, on northwest of this city, stems from the Alborz mountains and flows to Dashte Kavir, after crossing Mehdishahr county. Citadel Gate, the symbol of Semnan city, is one the tens of historical monuments of the city.