The Sava (Slovene pronunciation: [ˈsàːʋa], Serbo-Croatian: [sǎːʋa], Serbian Cyrillic: Сава) is a river in Central Europe, a right side tributary of the Danube. It flows through Slovenia, Croatia, along the northern border of Bosnia and Herzegovina, through Serbia, discharging into the Danube in Belgrade. Its central part is a natural border of Bosnia-Herzegovina and Croatia. The Sava forms the northern border of the Balkan Peninsula, and southern edge of the Pannonian Plain.