The steep, rocky sides of the Kablar Mt., its rocky boulders, and large forest complexes hide numerous species of well-preserved flora, with many relic species. Characteristic species in this gorge are the hornbeam (Carpinus betulus), Oriental hornbeam (Carpinus orientalis), small leaved linden (Tilia cordata), large leaved linden (Tilia platyphyllos), ash (Fraxinus ornus), smoketree (Cotinus coggygria),
mezereon (Daphne mezereum), spurgelaurel (Daphne laureola). The fauna is also very rich. Particularlyimportant species are the Hermann’s tortoise (Testudo hermanni), European pond terrapin (Emys orbicularis), Aesculapian snake (Elaphe longissima), fire salamander (Salamandra salamandra), peregrine falcon (Falco peregrinus), imperial eagle (Aquila chrysaetos), grey heron (Ardea cinerea), rock partridge (Alectoris graeca), pine marten (Martes martes), stone marten (Martes foina), badger (Meles meles), and other rare and threatened species.
Ten medieval monasteries are scattered like pearls over the gorge, representing a very attractive and significant monumental complex, unique for both the place and the time of its origins.
The spa Ovčar Banja is also positioned here, known for its medicinal thermal springs and beautiful sinter waterfalls and tubs on the brook Banjski Potok.

The Special Nature Reserve “Uvac” is posi­tioned in southwestern Serbia, and it encom­passes the gorge of the river Uvac and its tribu­taries Veljušnica, Kladnica and Tisovice.

This very attractive gorge has many unique me­anders and high limestone cliffs. A number of subterranean forms of karstic relief are devel­oped in the limestone rocks. Most frequent are the rock shelters, pits, and caves, among which particularly interesting is the Ušački cave system, the longest cave system in Serbia (6,185 m).

The large open water areas of lakes Sjeničko, Zlatarsko and Radoinjsko, with surrounding meadows and pastures, are the gathering plac­es for many bird species. So far, 104 species of birds were recorded, such as the golden eagle (Aquila chrysaetos), short-toed eagle (Circaetus gallicus), peregrine falcon (Falco peregrinus), goosander (Mergus merganser), corncrake (Crex crex), eagle owl (Bubo bubo) etc. Besides birds, there are many other interesting animals such as the Eurasian lynx (Lynx lynx), otter (Lutra lutra), and bats. The caves of Uvac are the only habitat of stenoendemic species of insects from the genera Remyella and Duvalius, and the mil­lipede Haasea lacusnigri microcorna.

The hallmark of the Reserve is the griffon vul­ture (Gyps fulvus), one of the rarest species of vultures in the Balkan Peninsula. A colony of the griffon vulture with 49 pairs today lives in the refugial habitats of this gorge, being the largest colony of this bird in the central Bal­kans.

The Marble cave (Mermerna Pećina) is positioned in southern Serbia, at the eastern edge of the Kosovo basin, in the village of Donje Gadimlje near Lipljan. It was formed in the massif of the hill Glavica, a branch of Gadimski Breg.

As an old, relic labyrinth of tectonically predisposed channels, the cave was formed in resistant dolomite marbles, and it is the largest object of this kind both in our country and in the world. So far, 1,260 m of the cave channels were explored. The basic morphological units of the Mermerna Pećina are the Entrance-, Western-, Northern-, and Eastern Gallery. All this units have complex networks and true labyrinths of channels, hallways, and halls, distributed at several horizons.

The abundance of all types of cave waters, from condensed and dripping, to flowing and stagnant, adds to the beauty of the cave. There are 29 permanent lakes in the cave, which is a rare occurrence. The largest number of these clear lakes is formed in compact marbles, and only a smaller number in the cave clay. The lakes are partly laying under the rock mass, thus it is not possible to measure their true dimensions. Subterranean karstic rivers that are coalescing into two separate watercourses are also interesting.

The Marble cave is very rich in jewels. All types of luxuriant multi-coloured cave jewellery can be found in the cave, from snow-white, blue, all shades of yellow, to red. The most numerous are stalagmites and stalactites, massif calcite pillars, cone-shaped flowstone, drapes, sinter pools, and translucent tubular jewels. Very rare aragonite jewellery is the greatest treasury of the cave. There are no other caves in the world where aragonites can be found in such quantity and variety of shapes as in the cave Mermerna Pećina.

Bogovinska cave

The Bogovinska cave (Bogovinska Pećina) is positioned in the village of Bogovina, at the eastern foothills of the massif of Južni Kučaj in eastern Serbia. It is developed in the karstified Mesozoic lime¬stone.

The Bogovinska Pećina was for a long time considered as the longest cave in Serbia, until the more detailed exploration of the Ušački cave system was done. The total length of the channels was several times corrected and, according to the latest study, it is 5,842 m. The cave channels are developed into three levels. The lower level – Ponorski Kanal, has a permanent flow. The upper level – Visoki Kanal, is dry. The central level – Glavni Kanal, occupies the largest part of the cave, and it is occasionally hydro¬logically active and gives the cave the character of a river spring cave.

This cave is inhabited by the very interesting fauna of cavernicolous arthropods. Among them, particularly significant are the stenoendemic pseudoscorpion Chthonius bogovinae, the pseudoscorpion Chthonius tetrachelatus, the terrestrial endemic crab Trichoniscus bogovinae, and the subtroglophile insect Choleva spadicea spadicea.

The cave system Samar – Veliki Pešter

The cave system Samar – Veliki Pešter is positioned in the northeastern part of the mountain group of Kalafat, which represents a segment of the Svrljiške Mts. The entire system is developed into three levels of cave-pit channels, with the explored length of 3,651 m.

This complex cave system is a river-tunnel system with two lost rivers, the Sudvek and the Žljebura. A subterranean cave spring of the gravitational-owerflow type is situated in the main channel of the Sudvek, and the hanging Lake Channel is a cave lake with two bottoms.

The spring part of the cave system consists of three karst springs: Jezava, Ripalo, and Toplik. Particularly beautiful is the hanging, siphon-overflow type spring Ripalo, with a waterfall 4 m high.

The cave, as an erosion cavity in the limestone, represents a form of the relief with secondarily deposited layers, of which the cave travertine has a particular aesthetic value. Especially attractive sinkhole pebbles and cave entrances, of which the most attractive is the entrance Samar with a limestone bridge over the large cave window, add to the beauty of this cave. A rich fossil fauna, with nine different genera of mammals of Holocene age, was found in the cave channels.

Stopić cave

The Stopić cave (Stopića Pećina) is positioned in the village of Rožanstvo at the northeastern slopes of the Zla¬tribor massif, in southwestern Serbia. The system is developed in karstified limestone of the Middle Triassic age of the eastern rim of the Inner Dinarids.

The cave Stopića Pećina consists of three units with entrances on the surface: Stopića Pećina, Chasm of Trnavski Brook, and Pećinica (Small Cave). The to¬tal length of the channels of the entire system is 1,594 m. The entrance into the cave Stopića Pećina is of large dimensions, 18 m tall and up to 40 m wide, so that it is one of the caves with the larg¬est entrances in Serbia.

After some hundred meters of the wide Main Channel (the Bright Hall and the Dark Hall) with windows, the cave is divided into two branches. The lower branch, River Channel, is hydrologically active and connected with the sinkhole of the Trnavski Potok. This branch is practically the subterranean flow of the brook Trnavski Potok. The upper branch, the Channel with Tubs, is dry and stretches in the direction of Pećinica.

At the beginning of the dry Channel with Tubs is the hall with numerous cascading sinter tubs. The largest tub is 12.5×3 m.The branch River Channel descends into the Main Channel through one of the cascades with overflowing water, creating a particularly attractive waterfall known as the “Source of Life”.

The cave is rich in other forms of cave jewels, such as the Hall with Baldachins, the Red Fireplace, the Coral Chimney, the erosive cracks, etc.The cave Stopića Pećina is the habitat of a stenoendemic subspecies of troglobitic trechine, Duvalius cvijici stopicensis. Rare guano-eating rove beetles – Quedius mesomelinus skoraszewskyi, Atheta spelaea, Deleaster dichrous, and Dianous coerulescens, were also found in the cave.

Prekonoška cave

The Prekonoška cave (Prekonoška Pećina) is hidden in eastern Serbia, near the village of Prekonoge. It is developed in karstified Mesozoic limestone of the anticline of the Svrljiške Mts.

The cave is in the form of a generally horizontal, winding, relatively simple channel, slightly branched in the second part, with halls rich in cave jewellery, and with a distinct colony of stalactites. Some twenty meters from the cave entry is the entrance into the much shorter channel of Golema Dupka, which is also a part of the cave system. The total length of the channels is 435 m.

This natural monument is significant as a habitat of rare species of the cave fauna. Two stenoendemic troglobitic arthropods – millipedes (Protoserbosoma tuberculata and Serboiulus lucifugus), live here, as well as the cave crab Moraria stankovitchi, and the trechine Duvalius bolei. The cave is a significant palaeontological and archaeological locality.

Resavska cave

The Resavska cave (Resavska Pećina) is positioned at the rim of the Divljakovačka valley near Despotovac, in eastern Serbia. The branched cave channels with large halls are divided into three levels. The total length of the channels is 447 m. The major units are the Entrance Hall, the Main Channel, the Crystal Hall, the Boban’s Hall, the Concert Hall, the Coral Channel, etc. All parts of the cave are rich in crystal calcite ornaments. Nearly all types of superbly ornamental cave jewellery are present, from massive pillars, stalagmites and stalactites, to coral growths on the wall of the channels, and small tubs with pearls at the bot¬tom of the cave.

The cave is inhabited with a very interesting fauna. Of cavernicolous arthropods, two species of troglophile spiders are known from this cave, Porhhomma convexus and Centromerus prope dacicus, the trogloxene pseudoscorpion Neobisium prope carpaticum, and the troglobitic millipede Serbosoma kucajensis, which is a stenoendemic species of the cave Resavska Pećina.

The cave Resavska Pećina is the first tourist cave in Serbia. It was arranged and open in 1972, and from that time it is a synonym of the speleological tourism In Serbia.

Lazarus cave

The entrance into the Lazarus cave (Lazereva Pećina) is above the river bed of the Lazarus River (Lazareva Reka) and Zlot Springs (Zlotsko Vrelo), immediately at the entry into the Lazarus Canyon, at the eastern part of the Kučajske Mts. The cave Lazareva Pećina morphogenetically corresponds to the spring part of the large fluvio-karstic subterranean system of the eastern Kučaj Mt., namely the Dubašnička karst plateau. The supposed length of this system is greater than 15 km, for which this cave is the longest cave in Serbia, although only 6,737 m of the subterranean channels were explored so far.

Characteristic representatives of the endemic troglobitic arthropod fauna are the crab Speleocyclops plutonis, millipede Serbosoma lazarevensis, wingless insects Pseudosinella problematica, Onychiurus zloti, Onychiurus trojan, and Arrhopalites zloti, trechine Duvalius stankovitchi georgievitchi, and troglophile pselaphine Bryaxis sculptifrons. More than twenty species of bats (Chiroptera) were recorded in the cave.

The most important findings of the fossil fauna are the remains of the cave bear (Ursus spelaeus), cave lion (Panthera spelaea), and cave hyaena (Crocuta spelaea). The entry part of the cave is a pre-historic archaeological locality.

Ceremošnja cave

The cave Ceremošnja is positioned in the northwestern part of the Homoljske Mts., 15 km from Kučevo. Ceremošnja is a sinkhole type cave, formed by the activity of the lost river Strugarski Potok, which today periodically flows through a part of the cave and sinks between the huge blocks of fallen rocks. The entrance into the cave is located at the left side of the blind valley of Struarski Potok, 14 m below its fossil dry valley.

There are two horizons of cave channels: an older one that is dry, and the younger one that is a water horizon. From the morpho-speleo¬logical aspect, there are five natural units: the Entry Channel, the Arena, the Sinkhole Hall, the Andesite Hall, and the Southern Channel. Each of the mentioned cave units is rich in cave jewellery of different forms and shapes. The most monumental form is the cave pillar “Under Eternal Guard” 7.5 m tall, built from white crystal calcite.

The fossils of the brown bear were discovered in the cave (Ursus arctos), cave bear (Ursus spelaeus), tur or bison (Bos/Bison), and cave hyaena (Crocuta spelaea). Of the cave fauna, particularly interesting is the coleopteran Bryaxis sculptifrons, an endemics of the Carpathian-Balkan karst. The length of the cave channels open for tourists is 431 m.

Rajko’s cave

Three kilometres from Majdanpek, at the headwaters of Mali Pek, is the plateau of a karst layer around 100 m thick, and with many speleological objects. The lost rivers Rajkova Reka, Jankova Reka, and Paskova Reka are cutting through the limestone. These rivers have built very complex cave systems and halls, rich in cave jewellery.

The river Rajkova Reka has built two horizons of cave channels: a higher one that is dry, and the lower one that is hydrologically active. The total length of the explored cave channels in the hydrographical system of the cave Rajkova Pećina is 2,304 m, of which the dry horizon is 1,174 m long, and the river horizon 1,130 m.

The cave Rajkova Pećina is distinct for its beauty and richness in jewellery, primarily markedly white, sparkling stalactites, stalagmites, pillars, and sinter flowstones that occur in a small number of caves in Serbia.

The cave is the habitat of bats, as well as a palaeontological locality with the fossil fauna – cave bear (Ursus spelaeus), wild boar (Sus scrofa), and red deer (Cervus elaphus ).

Within the limits of a natural asset, apart from the cave Rajkova Pećina, there are several other morphological and hydrological values: Paskova Pećina, Jankova Pećina, the sinkhole of the Rajkova Reka and Paskova Reka, the Summer Stage (a former sinkhole of the Paskova Reka), dry valleys of the Rajkova Reka and Paskova Reka, rocky cliffs, deep valleys, and the headwaters of the river Mali Pek.

Potpećka cave

The Potpećka cave (Potpećka Pećina) is positioned at the foothills of the vertical limestone cliff of the hill Gradina, at the right, flat riverbank of the river Djetinja, in western Serbia. It had a grandiose cave opening, 50 m tall, and several levels of channels, of which 555 m have been explored. There are two main morphological units in the cave Potpećka Pećina, the Upper Cave and the Lower Cave. The entrance hallway, named Hangar, is common for both cave units.

The hallway Hangar stretches for 55 m in the form of an imposing subterranean canyon with boulders, at the bottom of which winds the riverbed of the cave river Petnica. The Upper Cave, or the Hall Under the Dome, is a huge subterranean room from which the cave chan¬nels with numerous halls branch. These halls are more than 15 m wide and up to 8 m tall (the Cvijić’s Hall). The Lower Cave consists of the Lake Channel and the Hanging Channel. The Lake Channel ends in a lake 15 m long.

This cave is a spring cave, with an intermittent watercourse of the rivulet Petnica. The lake of the Lower Cave represents the spring of the river Petnica. There is a sinkhole at the bottom of the lake, through which the water flows to the spring in front of the cave entrance. The first spring, Veliki Bent, is positioned 40 m downstream from the cave, and the other spring, Mali Bent, is positioned some twenty meters further downstream.

Interesting forms of the crystal ornaments can be found in the cave, such as flowstones, drapes, stalactites, stalagmites, and pillars. The cave Potpećka Pećina is the habitat of bats. The archaeological remains indicate that the cave was inhabited by humans already in the pre-historic period.

The primary, initial agent in formation of the soil pyramids is the rain and its runoff. Mechanical destruction occurs under the strokes of the raindrops, after which the clayey components are being dissolved and removed from the surface layer, and the initial, miniature erosive furrows are being formed. Concentrated flow and runoff of the rainwater occurs along these furrows, as well as removal of the more and more larger quantities of the loose material. However, the material under the rocky blocks was protected from this “bombardment” of raindrops and runoff, so that it remained on the slope in the form of short primary pillars with “tables”. Runoff of the material and cut¬ting of the trenches occurred not only by gravitation, down the trenches, but transversely as well, between the pillars.

Apart from this geomorphological erosive phenomenon, there are two hydrological rarities in Djavolja Varoš – the two very mineralised springs, Djavolja Voda and Crveno Vrelo.

This entire complex of outstanding magnetism represents a unique natural laboratory, with particular scientific, educational, and cultural significance.

The area is located at the border of the continental and Mediterranean climate and, combining the characteristics of both climate types, it is favourable for many species of plants and animals. On one side, it represents the southern border of distribution for continental species of flora and fauna, and on the other side, the northern border of distribution for species characteristic for the Mediterranean.
Polydominant thermophilous forests and thickets of the downy oak (Quercus pubescens), Turkey oak (Quercus cerris), Italian oak (Quercus frainetto), Oriental hornbeam (Carpinus orientalis),
ash (Fraxinus ornus), prickly juniper (Juniperus oxycedrus), Turkish filbert (Corylus colurna), and many other species, among which there are numerous Tertiary relics, prevail in this area. The characteristic species of animals are the snake-eyed skink (Ablepharus kitaibelii), ocellated skink (Chalcides ocellatus), large whip snake (Coluber caspius), red-rumped swallow (Hirundo daurica) northern goshawk (Accipiter gentilis), Levant sparrowhawk (Accipiter brevipes).
The richness of the flora and fauna, the preserved morphology of the terrain and the cultural monument of extraordinary significance, the Monastery of St. Prohor Pčinjski from the 11th century, make this area particularly important from the aspect of conservation of natural and cultural-historical values.

The main function of the reserve is the conserva¬tion of the natural watercourse characteristic for lowland areas, as well as the preservation of wet¬land habitats with significant biological diversity.

More than 250 phytoplankton and 190 zooplank¬ton species were determined within the Reserve. Furthermore, this area is inhabited by 60 spe¬cies of fungi and around 700 species of vascular plants. The most important plant species are the white water lily (Nymphaea alba), yellow pond lily (Numphar luteum), greater spearwort (Ranuncu¬lus lingua), Urtica kioviensis, water soldier (Strati¬otes aloides), and waterwheel plant (Aldrovanda vesiculosa), a Tertiary relic for which it was long thought that it has disappeared from Serbia.

Of 21 species of fish, particularly significant is the European mudminnow (Umbra krameri), for which Zasavica is the only habitat in Serbia.

The fauna of amphibians (13 species) and reptiles (14 species) is very rich, as well as the fauna of birds. Among 185 bird species, particularly inter¬esting are the penduline tit (Remiz pendulinus), little bittern (Ixobrychus minutus), and ferrugi¬nous duck (Aythya nyroca). Of 30 species of mam¬mals, the European beaver (Castor fiber), the spe¬cies that was reintroduced to its natural habitats in Zasavica after being extinct in Serbia for a long time, deserves a particular attention.

This reserve is significant for the preservation of autochthonous breeds of domestic animals as well, such as the swallow-bellied Mangulitsa pig, the Balkan donkey, and the Podolian cow.

It is positioned in central Banat, in the alluvial plane between the rivers Tisa and Begej. It has a shape of the letter “S” slightly inclined towards the southwest-northeast direction. The relief of this area is of a definite lowland type, and the most significant hydrological asset of the reserve, along with a number of smaller ponds, channels, and stagnant waters, are the old riverbeds of the river Begej – Carska Bara, Tiganjica, and Perleska Bara.

Around 500 plant species with the Pannonian, Pontic, Mediterranean, and continental distribution range were described within the Reserve, with numerous endemic, subendemic, relic, and rare species. Particularly interesting are the white water lily (Nymphaea alba) and thistle (Cirsium brachycephalum). Furthermore, the presence of 328 taxa of phytoplankton was determined within the Reserve, as well as a number of insect species (Dorcus parallelopipedus, Apatura metis…), 24 species of fish (Rhodeus sericeus am¬arus, Misgurnus fossilis…), 11 species of amphibians (Triturus vulgaris, Hyla arborea…), 5 species of reptiles (Emys orbicularis, Natrix natrix…), 50 species of mammals, among which the wild cat (Felis silvestris) and otter (Lutra lutra).

The greatest assets of the Reserve are the birds, first of all the waterfowl. The presence of 250 species such as Dalmatian pelican (Pelecanus crispus), white-tailed eagle (Haliaeetus albicil¬la), and corncrake (Crex crex) was determined in the Reserve.

This lowland area is characterized by flat or slightly undulating relief with meanders, by-channels, old river courses, river islets, and ridges. Elongated ridges and swales are interchanging and stretching more or less parallel to the river course and to by-channels, which has a strong influence on the distribution of the flooding water and the level of the ground water. The area consists of marsh forests cut with ponds, swamps, wet meadows, reeds and shrubbery.

Gornje Podunavlje is a significant biodiversity center of Serbia. Its vegetation is built of 57 herbaceous, forest, and shrubby plant communities. Most communities are of the primary character, which illustrates the significant ecosystem diversity. Many fragile ecosystems are preserved, and represent the international priority in protection.

More than 1,000 plant species were determined, among which there are several critically endangered species in Serbia, such as the water violet (Hottonia palustris), mare’s tail (Hippuris vulgaris), and greater spear wort Ranunculus lingua). This area is inhabited by 60 species of butterflies, 55 species of fish, 11 species of amphibians, 9 species of reptiles, 230 species of birds, and 51 species of mammals. It is an important spawning ground and migratory route for fishes, a nesting site of the white-tailed eagle (Haliaeetus albicilla) and black stork (Ciconia nigra), and the habitat of the largest red deer (Cervus elaphus) and wild boar (Sus scrofa) populations in Serbia.

The Reserve is a significant trans boundary area that forms a natural unity with the protected marshlands in Croatia and Hungary with which it represents the largest inundation area in the middle course of the Danube in Europe.

Obedska Bara is one of the oldest protected natural assets in the world. The first administrative protection dates from 1874. Following the revision of the area in 1994, it was given the status of the Special Nature Reserve.

The exceptional richness and diversity of ecosystems of Obedska Bara represent one of its fundamental values. In scope of the reserve, more than 30 aquatic, swamp, forest, and meadow communities were described. So far, around 180 species of fungi, 50 species of mosses, 500 species of vascular plants, more than 200 species of zooplankton, over 300 species of insects, 16 species of fish, 13 species of amphibians, 12 species of reptiles, 222 species of birds, and 50 species of mammals were recorded. The beaver (Castor fiber) was recently reintroduced to Obedska Bara.

The integrity and patchiness of the ecosystems of Obedska Bara are conditioned first of all by the microrelief and cyclic processes in nature related to seasonal flooding of the reserve, upon which the survival of the autochthonous biota and its communities depends. In current time, many of these natural rarities are preserved, but Obedska Bara and its natural diversity are more threatened each day by the succession of the vegetation, by disturbance of the water regime, and by human activities.

The”golden age” of Obedska Bara, described in literature, lasted during the 19th century and the first decades of the 20th century. It is considered that as much as 15,000 pairs nested at that time in the colony of herons and cormorants. Such concentration has never been recorded in Serbia again, and the current colony consists of 600 pairs of seven species of herons and cormorants.

The entwined natural and cultural heritages are a special value of Obedska Bara. The Church of Mother Angelina and old town Kupinik is situated in the area of the reserve.