A subregion is a part of a larger geographical region or continent. Cardinal directions are commonly used to define subregions. There are many criteria for creating systems of subregions; this article is focusing on the United Nations geoscheme, which is a changing, constantly updated, UN tool based on specific political geography and demography considerations relevant in UN statistics.
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Sub-region in the context of Southeast Europe
Southeast Europe or Southeastern Europe is a geographical sub-region of Europe, consisting primarily of the region of the Balkans, as well as adjacent regions and archipelagos. There are overlapping and conflicting definitions of the region, due to political, economic, historical, cultural, and geographical considerations.
Sovereign states and territories that may be included in the region are Albania, Bosnia and Herzegovina, Bulgaria, Croatia (alternatively placed in Central Europe), Greece (alternatively placed in the broader region of Southern Europe), Kosovo, Montenegro, North Macedonia, Romania (alternatively placed in Eastern Europe), Serbia, and the European part of Turkey (alternatively placed in the broader region of Southern Europe, also in Western Asia with the rest of the country). Sometimes, Cyprus (most often placed in West Asia), Hungary (most often placed in Central Europe), Moldova (most often placed in Eastern Europe), and Slovenia (most often placed in Central Europe) are also included due to cultural or historical factors and affiliation.
View the full Wikipedia page for Southeast Europe