The central ridge of the eastern Stara Planina mountains, covered by broadleaved deciduous forests, pasture and arable land. A great number of minor but distinct ridges slope down north and south to the valleys of the Rivers Titcha and Luda Kamtchia. These side-valleys are narrow and deeply incised, with steep slopes. The underlying rock is limestone and sandstone, and there are some sand quarries in the region. The forests are dominated by Fagus or Quercus, with Carpinus in some places, and there are natural mixed forests of Abies and Fagus in the western part of the area.
An important breeding area for globally threatened species (Crex crex, Aquila heliaca) as well as for Ciconia nigra, a wide variety of large raptors, and two woodpeckers (Picus canus and Dendrocopos medius). Species of global conservation concern that do not meet IBA criteria: Phalacrocorax pygmeus (3-12 on passage), Pelecanus crispus (max. 1 on passage), Aythya nyroca (1 breeding pair; 4-16 on passage), Aquila clanga (max. 1 on passage), Falco naumanni (max. 3 pairs). Significant proportion (³1%) of national population breeding at site: Bubo bubo (2-4 pairs).
BirdLife International (2019) Important Bird Areas factsheet: Kotlenska Mountain. Downloaded from http://www.birdlife.org on 23/05/2019.