Southeast Europe
This concept is based on the boundaries of the Balkan peninsula. The countries that have been described as being entirely within the region are: Albania, Kosovo, Bosnia and Herzegovina, Bulgaria, Macedonia and Montenegro.
Balkans
The Balkan Peninsula is bounded by the Adriatic Sea to the west, the Mediterranean Sea (including the Ionian and Aegean seas) and the Marmara Sea to the south and the Black Sea to the east. Its northern boundary is often given as the Danube, Sava and Kupa Rivers. The Balkan Peninsula has a combined area of about (slightly smaller than Spain). It is more or less identical to the region known as Southeastern Europe.