Sistan

or Seistan

Extensive border region, eastern Iran and southwestern Afghanistan. Most of its sparse population and about two-fifths of its area lie in Iran. It comprises a large marshland depression with a true desert climate. It is the reputed homeland of the legendary Kayanian dynasty of Persia and played an important part in Persian history, especially under the S (1502–1736). In the 19th century it was the centre of a dispute between Persia and Afghanistan that led to the establishment of their modern frontier.

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