The Darial Gorge (Georgian: დარიალის ხეობა, Darialis Kheoba; Russian: Дарьяльское ущелье; Ossetian: Арвыком, Arvykom; Ingush: Даьра Аьле, Dära Äle) is a river gorge on the border between Russia and Georgia. It is at the east base of Mount Kazbek, south of present-day Vladikavkaz. The gorge was carved by the river Terek, and is approximately 13 kilometres (8.1 mi) long. The steep granite walls of the gorge can be as much as 1,800 metres (5,900 ft) tall in some places.
The Darial originates from Dar-i Alān (در الان) meaning "Gate of the Alans" in Persian. The Alans held the lands north of the pass in the first centuries AD. It has been fortified in ancient times by the Romans and Persians; the fortification was variously known as the Iberian Gates[a] or the Caucasian Gates. The pass is mentioned in the Georgian annals under the names of Darialani; Strabo calls it Porta Caucasica and Porta Cumana; Ptolemy, Fortes Sarmatica; it was sometimes known as Porta Caucasica and Portae Caspiae (a name bestowed also on the "gate" or pass beside the Caspian Sea at Derbent); and the Tatars call it Darioly.