A transcontinental city is a city occupying portions of more than one continent. Such a city may be transcontinental by virtue of crossing a continental boundary on land or of including islands associated with a continent other than that where the city is based. Due to the nebulous nature of the boundaries between Europe and Asia, Istanbul in Turkey is the only naturally occurring transcontinental city. Since the Ural River is usually, but not always, considered the boundary between Europe and Asia, two cities on that river can be considered transcontinental. A fourth city straddles the Suez Canal, the boundary between Africa and Asia, but this particular boundary is man-made. The following are examples of transcontinental cities listed alphabetically: Atyrau, a city in western Kazakhstan divided by the mouth of the Ural River. Almost all of it lies in Asia, but a small portion extends into Europe. [ ] Istanbul, the largest city of Turkey and best-known example. The Bosporus Strait separates its European and Asian portions. It is coterminous with Istanbul Province, with 65% of its residents in the 19 districts of the European portion and 35% in the 12 districts of the Asian portion. Orenburg, a Russian city on the Ural River. Most of it is considered in Europe, but part of its south side crosses the Ural into Asia. Suez, an Egyptian city on the Suez Canal and coterminous with the Suez Governorate. Almost all of it is considered part of Africa, but a small portion extends eastward into Asia. Magnitogorsk, a Russian city on the Ural River. Cities which, although not transcontinental cities, lie very close to continental boundaries and are also hubs of transcontinental metropolitan areas: Çanakkale, an Asian city in Turkey with the Dardanelles Strait separating it from its European suburbs. It is part of the transcontinental megalopolis of Istanbul-Bursa-Çanakkale, which includes all of metropolitan NW Turkey. Ismaïlia, an African city in Egypt with the Suez Canal separating it from its Asian suburbs. Oral, Kazakhstan, a European city with the Ural River separating it from its Asian suburbs. Port Said, an African city in Egypt with the Suez Canal separating it from its Asian suburbs.