Afghanistan–Iran border

[1] The border begins at the tripoint with Turkmenistan in the Harirud river before proceeding overland just to the east of the Iranian town of Taybad.

The border then follows a series of short straight lines, passing through the Daryache-ye Namakzar and the Daqq-e Patergan salt lakes; two 'beaks' of Iranian territory protrude into Afghanistan along this section.

The border is then formed of a long straight line segment going southwest to the tripoint with Pakistan at the Kuh-i-Malik Salih mountain.

The border between Qajar Iran and Afghanistan was formalised in the period 1872–1935 by a series of third-party arbitrations, stemming from the Treaty of Paris (1857) in which Iran and Afghanistan agreed to refer any dispute between them to Britain for arbitration (at this time Britain controlled large parts of India, including what is now Pakistan).

A rough delimitation was proposed in 1872 by a committee headed by Sir Frederic John Goldsmid following a line from Banda to Kuh-i-Malik Siah (a hill at the modern Afghanistan-Iran-Pakistan tripoint) via the Helmand River.