Semnan province is located on the Silkroad and east-west corridor and this has given its importance in different historical eras. A large number of caravanserais in this province confirms this fact.
Semnan is a large province but has a low population density, mostly because of its arid climate.
Semnan province is surrounded by Tehran, Mazandaran, Golestan, North Khorasan, Razavi Khorasan, South Khorasan, Isfahan and Qom provinces.
Northern parts of this province that lie on Alborn mountain have colder weather, while the southern parts have arid and warm weather.