Bulgaria - Bulgarian language : България, pronounced [bəlˈɡarija]), officially the Republic of Bulgaria (Република България, Republika Bulgaria, [rɛˈpublika bəlˈɡarija]), is a country in the Balkans in south-eastern Europe. Bulgaria borders five other countries: Romania to the north (mostly along the River Danube), Serbia and the Republic of Macedonia to the west, and Greece and Turkey to the south. The Black Sea defines the extent of the country to the east.