Istanbul Istanbul Istanbul (, or or ; ), historically known as Byzantium and before 1924 as Constantinople, is the most populous city in Turkey and the country's economic, cultural, and historic center. Istanbul is a transcontinental city in Eurasia, straddling the Bosporus strait (which separates Europe and Asia) between the Sea of Marmara and the Black Sea. Its commercial and historical center lies on the European side and about a third of its population lives on the Asian side. The city is the administrative center of the Istanbul Metropolitan Municipality (coterminous with Istanbul Province), both hosting a population of around 15
Korea Strait Korea Strait into the western channel and the Tsushima Strait. The western channel is deeper (up to 227 meters) and narrower than the Tsushima Strait. A branch of the Kuroshio Current passes through the strait. Its warm branch is sometimes called the Tsushima Current. Originating along the Japanese islands this current passes through the Sea of Japan then divides along either shore of Sakhalin Island, eventually flowing into the northern Pacific Ocean via the strait north of Hokkaidō and into the Sea of Okhotsk north of Sakhalin Island near Vladivostok. The water-mass characteristics vary widely because of the low-salinity waters