The Hari River ( or ; ) or Herat River is a river flowing from the mountains of central Afghanistan to Turkmenistan, where it forms the Tejend oasis and disappears in the Karakum Desert. In its lower course, the river forms a northern part of the border between Afghanistan and Iran, and a southeastern part of the border between Turkmenistan and Iran. In Turkmenistan it is known as the Tejen or Tedzhen river and passes close to the city of Tedzhen. To the Ancient Greeks it was known as the Arius. In Latin, it was known as the Tarius. History One theory identifies the Rigvedic Sarayu river with the Hari river. A Buddhist monastery hand-carved in the bluff of the river Harirud existed in the first centuries during the prevalence of Buddhism. The artificial caves revealed testimony of daily life of the Buddhist monks. Course The river originates in the eastern part of Ghor Province in the Baba mountain range, part of the extensions of Hindu Kush system, and follows a relatively straight course to the west. Still some upstream from Herat the river meets the Jam River at the site of the Minaret of Jam, the second tallest ancient minaret in the world at . In western Afghanistan the Hari Rud flows to the south of Herat. 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. The Iran–Turkmenistan Friendship Dam is on the river. The Afghan-India Friendship Dam (Salma Dam) is a hydroelectric and irrigation dam project located on the Hari Rud in Chishti sharif District of Herat Province in western Afghanistan. The average annual discharge of the Hari Rud is about 55 m3/s, but during a spring flood in 1939 the discharge went up to 1090 m3/s. In 2000, the river dried up completely during a 10-month drought. Bridges Pulkhatyn Bridge An unused stone-bridge of five arches, this falls in the Ahal Region of Turkmenistan. It is about north of Iran–Turkmenistan Friendship Dam. Pulkhatyn translates to "wealthy woman." In Turkmen lore, the custodian of the bridge was a woman who made a fortune by taxing all travelers; Alexander the