Most of the area is covered by mountain ranges running from the northwest to southeast. The main ranges are the Balkan mountains (Stara Planina in Bulgarian language), running from the Black Sea coast in Bulgaria to the border with Serbia, the Rilo-Rhodope massif in southern Bulgaria, northern Greece and southeastern North Macedonia, the Dinaric Alps in Bosnia and Herzegovina, Croatia and Montenegro, the Šar massif which spreads from Albania to North Macedonia, and the Pindus range, spanning from southern Albania into central Greece and the Albanian Alps. The highest mountain of the region is Rila in Bulgaria, with Musala at 2925 m, Mount Olympus in Greece, being second at 2917 m and Vihren in Bulgaria being the third at 2914 m. The karst field or polje is a common feature of the landscape.