[3][4] A Buddhist monastery hand-carved in the bluff of the river Harirud existed in the first centuries during the prevalence of Buddhism.

The valley around Herat with the Paropamisus Mountains (Selseleh-ye Safēd Kōh) on the right river bank was historically famous for its fertility and dense cultivation.

After Herat, the river turns northwest, then north, forming the northern part of the border between Afghanistan and Iran.

Farther north it forms the south-eastern part of the border between Iran and Turkmenistan.

"[9] In Turkmen lore, the custodian of the bridge was a woman who made a fortune by taxing all travelers; Alexander the Great had apparently refused to pay this fee and crossed further downstream.