Kazakhstan – Russia

The 7,644 kilometer (4,750 mi) international boundary separating the Russian Federation and the Republic of Kazakhstan is known as the Kazakhstan-Russia frontier (Russian: ааcтанско-россиска раниа, Kazakh: аастан-есе екарас). After the border between Canada and the United States, it is the longest continuous international border in the world and the second longest overall. It is situated where the administrative-territorial border between the Russian Soviet Federative Socialist Republic and the Kazakh Soviet Socialist Republic once stood.

The boundary, which begins in the west at the Caspian Sea and generally runs in a west-east direction to the tripoint with China, is exceedingly complicated in some locations. Although rivers like the Maly Uzen, Ural, and Uy are used in some places, the border is largely made up of overland boundaries that cross the Eurasian Steppe. The border crosses Botkul Lake. The border passes via the Altai Mountains in the far eastern region.

Length: 7,644 kilometers