The Balkans is the historic and geographic name used to describe a region of southeastern Europe. The region has a combined area of 550,000 km² and an approximate population of 55 million people. The archaic Greek name for the Balkan Peninsula is the Peninsula of Haemus (Χερσόνησος του Αίμου). The region takes its name from the Balkan Mountains which run through the centre of Bulgaria into eastern Serbia.