Stara planina (Old Mountain) belongs to the group of chain mountains and its main range extends from town Zajecar to the Black Sea, at the distance of about 550 km. Its other name is Balkans and whole Balkans Peninsula got name by it. Total area of Stara Planina massif is spreading across Serbia in 1802 square kilometers. It is a protected monument of nature with numerous reserves, waterfalls, relict plant and animal. Stara planina is located on Serbian-Bulgarian border, on the territory of minicipalities of Zajecar, Knjazevac, Pirot and Dimitrovgrad. The mountain is 600 km long, of which the area of 100 km in lenght and between 4 and 30 km in width is placed on the territory of Serbia, while the larger part of it is on the territory of Bulgaria. Height differences range from 200 to 2.160 meters, which is at the same time the height of the highest peak of Stara Planina – Midzor. Of the entire surface area of 1,250 km2, 1,143 km are under protection within the Natural Park Stara Planina, what makes 91,44% of a total territory.
Forests cover larger part of the mountain (40%), while the rest is covered with agricultural land (grasslands, arable land, orchards and vineyards). The region deserved the status of the natural park because of its developed but preserved geological diversity and the specific diversity of its wildlife.
The hiking tour consists of:
· Minibus transfer Kalna – RavnoBučje 45 min
· Hiking tour 5h (with breaks)
· Break in mountain house 1h
· Minibus transfer mountain house - Kalna 45 min
· Hiking tour Stara planina Hiking tour Stara planina On the mountain Stara Planina 52 plant communities is found and they cross on varios habitats, depending on natural factors. The communities of special value are peatlands, that are usually located in beech and evergreen forest and at the tops of the mountain.
Flora of the mountain Stara Planina contains 1,200 species and subspecies of higher plants of which 115 species are endemic, while 40 of them are natural rarity of Serbia. Unfortunately, 50 plant species found on the list of endangered European flora, while some of them are classified into category of critically endangered. The moss is represented in 51 species.
In the mountain Stara Planina habitat it is noted 203 bird species, of which are nesting bird that mostly represent rare or endangered species. There are 30 species of mammals present, 18 species of reptile and 6 species of amphibians.There are also 26 species of ichtyofauna, while it is know for sure that 116 species of butterflies are present.
The product of settling of calcium carbonate in cold-water regime and under biological and physic-chemical influence. It is located along the way Knjazevac-Kalna-Pirot. Accumulation of bigar in Bigar stream valley is in erosive phase. The stream is carved into the reservoir and eroded in most parts. Three visible parts where bigar is covered with slopes and fluvial material are clearly expressed today. For the formation of the bigar accumulation it is important a phenomenon of hot water spring at the right side of the Surdup stream because the water from the spring directly affects the ravines valley of Surdup stream. Considering that Surdup has a periodic flow, while water from spring flow throughout the year, residents have a name for this parts of the stream after spring, and it is Bigar Stream. There is a waterfall in the valley with over two cascades, height of 35 meters, which is also the mouth of the river Stanjska. A waterfall with over two cascades in two strong streams descends into the valley of the river Stanjska.
The relief of the mountain Stara Planina is of tectonic origin, shaped by the water influence and karst processes, characterized with great dissection, with cleaved and deep valleys of the rivers.
Geological shape of the mountain is pretty simple. It is made of two rock types – Permian red sandstone the Triassic limestone and dolomites. Regardless of this fact, the mountain Stara Planina is a treasury of geological heritage because of the sediments diversity of different ages.
Babin Zub is one of the hightest peaks of mountain Stara Planina, known by its characteristical group of rocks, consisted of quartz sandstone. During the time, the basic rocky mass of BabinZub's Mountain is converted into an upper and a lower rock, both irregular shape. Extremely dominate the environment since it is almost without vegetation and in contrast with the surrounding greenery. Nearby this interesting peak there are many springs of extremely cold and clear mountain water. Beside great number of these geomorhological shapes, Babin Zub is also known as one of the most beautiful viewpoints of the mountain Stara Planina.