Croatia stretches along the Adriatic coast (narrowing north–south; the major ports being Rijeka, Pula, Zadar, Sibenik, Split and Dubrovnik) with a larger inland area (running west–east from Zagreb to the border with Serbia & Montenegro). The northern two-thirds of this border are formed by the River Danube. The country borders Slovenia and Hungary to the north, Serbia & Montenegro to the east and Bosnia & Herzegovina (southeast from Zagreb; northeast from the Adriatic coastline).