Iran–Turkmenistan border

Iranian and Turkmen boundary markers

The Iran–Turkmenistan border is the national border separating the countries of Iran and Turkmenistan. It is 1,148 km (713 miles) in length and runs from the Caspian Sea to the tripoint with Afghanistan. The Turkmen capital Ashgabat is only 15 miles north of this boundary, and Mashhad (Iran's second largest city) is 47 miles south of it.