The border between Azerbaijan and Iran is uniquely split into two separate sections by Armenian territory. The longer eastern section connects mainland Azerbaijan to Iran, while the western section borders Iran and Azerbaijan’s Nakhchivan exclave. For mainland Azerbaijan, you have two primary crossings: Astara and Bilasuvar. The Astara crossing is particularly interesting because the town of the same name exists in both countries, separated by the Astarachay River. You can literally walk from one town center to the other across the bridge, observing the flow of local life and commerce in a bustling border environment. The Bilasuvar crossing is a more standard highway checkpoint on the open Mugan plain. For the Nakhchivan exclave, crossings at Jolfa and Poldasht provide vital links, often used by Iranians for shopping and trade. The entire border follows the Aras River for a significant portion, a historic boundary between the Persian and Russian empires that was formally established by the Treaties of Gulistan (1813) and Turkmenchay (1828). Crossing this border marks a significant cultural shift, from the Turkic and post-Soviet world of Azerbaijan to the distinct Persian culture of Iran.