DARIAL, a gorge in the Caucasus, on the east of Mt. Kasbek, pierced by the river Terek for 8 m. between vertical walls of rock (5 ft.). It is mentioned in the Georgian annals, by Strabo and by Ptolemy. Being the only available passage across the Cau casus, it has been fortified at least since I 5o B.C. In Russian poetry it has been immortalized by Lermontov. The present Rus sian fort, Darial, which guards this section of the Georgian mili tary road, is at the northern issue of the gorge, at an altitude of feet.