world's highest arch dam (completed 1980), located on the Inguri River in western Georgia near the point at which the river leaves the Caucasus Mountains on its way to the Black Sea. It is a huge 892-foot- (272-metre-) tall double-curvature arch dam with a crest length of 2,231 feet (680 m). The dam was built of interlocking stacks of concrete monoliths laid over reinforced limestone bedrock. The five-unit power plant associated with the dam has a planned power capacity of 1,300 megawatts.