Bulgaria is among the countries with the most forests in Europe.
In ancient times, they covered almost the entire territory of the nowadays state. The rapid development of the region in the Antiquity and in the Middle Ages has had its impact. Today forests cover one third of the country's territory. Although most of the forests are of natural origin, only about 4% of them have survived as primeval forests that are unaffected by human activity. The Central Balkan National Park is the largest, well protected massif of primeval and ancient beech forests in Bulgaria. The National Park's forests are composed of 71% beech, which accounts for 5.2% of Bulgaria's total beech forest area.
It is assumed that the extensive expansion of the beech in the Balkan Mountains began five to six thousand years ago.
The 9 World Heritage properties of pure and mixed beech forest stands in Bulgaria are all located in strict nature reserves within the Central Balkan National Park. Compared to the other World Heritage properties in the same Moesian-Balcanic beech forest region, the bedrock in this beech forest region is composed of magma-plutonic, sedimentary, and metamorphous rock. They represent the whole variety of different altitudinal zones, from small beech trees on rocks at the tree line at 1,700 meters above sea level in the Sokolna and Peeshti Scali reserves to the beech giants with a height of 50 meters in the Boatin reserve. The latter is the only component part that represents the genetic diversity of the Moesian Beech (Fagus sylvatica var. moesiaca).