The 2,500 km border between Iran and the USSR on land and the Caspian Sea
A Map of Persia from 1922, a Diagram of the Border with the USSR and a Map of Present-Day Iran.
The shared border between Iran and the USSR: 2,500 km of land border, Azerbaijani-Iranian, Armenian-Iranian and Turkmen-Iranian, together with the maritime border on the Caspian Sea

