The Darial Gorge is found in the Caucasus in modern day Georgia near the border with Russia. It is at the east base of Mount Kazbek, pierced by the river Terek for a distance of 8 meters between vertical walls of rock (5900 feet). It is mentioned in the Georgian annals under the names of Ralani, Dargani, Darialani; the Persians and Arabs knew it as the Gate of the Alans; Strabo calls it Porta Caucasica and Porta Cumana; Ptolemy, Fortes Sarmatica; it was sometimes known as Portae Caspiae (a name bestowed also on the "gate" or pass beside the Caspian Sea at Derbent); and the Tatars call it Darioly. Being the only available passage across the Caucasus, it has been long fortified -- at least since 150 B.C. In Russian poetry it has been immortalized by Lermontov. The Russian fort, Darial, which guarded this section of the Georgian Military Road, is at the northern end of the gorge, at an altitude of 4746 feet.

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