Georgia is located in the mountainous South Caucasus region of Eurasia, straddling Western Asia and Eastern Europe between the Black Sea and the Caspian Sea. Georgia's northern border with Russia roughly runs along the crest of the Greater Caucasus mountain range - a commonly reckoned boundary between Europe and Asia. In Philip Johan von Strahlenberg's 1730 definition of Europe, which was used by the Russian Tsars and which first set the Urals as the eastern border of the continent, the continental border was drawn from the Kuma-Manych Depression to the Caspian Sea, thereby including all of Georgia (and the whole of the Caucasus) in Asia.