The authors of these pages have divided the protected territories into two main groups. In the first group fall less protected natural sites, classified as natural landmarks and protected sites according to the legislation of the Republic of Bulgaria. The second group includes natural sites for which the state uses stricter measures for protection and special care - these are the natural parks and reserves. The natural landmarks and protected sites are described by districts (Montana, Vratza and Vidin) so that the readers can easily find information about them.

The natural parks and reserves are less in number and are described separately with detailed information about the biodiversity in them. On the territory of the Northwestern Region is located the "Vrachanski Balkan" natural park. Within the limits of the park are located some reserves with short description about their flora and fauna.