Karst topography is a landscape formed from the dissolution of soluble rocks such as limestone and gypsum. It is characterized by underground drainage systems with sinkholes and caves and it has been documented for more weathering-resistant rocks, such as quartzite, given the right conditions. Subterranean drainage may limit surface water, with few to no rivers or lakes, the English word karst was borrowed from German Karst in the late 19th century. The German word came into use before the 19th century, according to the prevalent interpretation, the term is derived from the German name for the Karst region, a limestone plateau above the city of Trieste in the northern Adriatic. Scholars disagree, however, on whether the German word was borrowed from Slovene, the Slovene common noun kras was first attested in the 18th century, and the adjective form kraški in the 16th century. The Slovene words arose through metathesis from the reconstructed form *korsъ, the word is of Mediterranean origin, believed to derive from some Romanized Illyrian base.
It has been suggested that the word may derive from the Proto-Indo-European root karra- rock, the name may be connected to the oronym Karsádios oros cited by Ptolemy, and perhaps to Latin Carusardius. The development of karst occurs whenever acidic water starts to break down the surface of bedrock near its cracks, as the bedrock continues to degrade, its cracks tend to get bigger. As time goes on, these fractures will become wider, if this underground drainage system does form, it will speed up the development of karst formations there because more water will be able to flow through the region, giving it more erosive power. The carbonic acid that causes karstic features is formed as rain passes through the atmosphere picking up carbon dioxide, once the rain reaches the ground, it may pass through soil that can provide much more CO2 to form a weak carbonic acid solution, which dissolves calcium carbonate. The oxidation of sulfides leading to the formation of acid can be one of the corrosion factors in karst formation.
As oxygen -rich surface waters seep into deep anoxic karst systems, they bring oxygen, sulfuric acid reacts with calcium carbonate, causing increased erosion within the limestone formation. This chain of reactions is, This reaction chain forms gypsum, the karstification of a landscape may result in a variety of large- or small-scale features both on the surface and beneath. On exposed surfaces, small features may include solution flutes, limestone pavement, medium-sized surface features may include sinkholes or cenotes, vertical shafts, disappearing streams, and reappearing springs. Large-scale features may include limestone pavements and karst valleys, mature karst landscapes, where more bedrock has been removed than remains, may result in karst towers, or haystack/eggbox landscapes. Beneath the surface, complex underground systems and extensive caves. Some of the most dramatic of these formations can be seen in Thailands Phangnga Bay, calcium carbonate dissolved into water may precipitate out where the water discharges some of its dissolved carbon dioxide.
Rivers which emerge from springs may produce tufa terraces, consisting of layers of calcite deposited over extended periods of time, in caves, a variety of features collectively called speleothems are formed by deposition of calcium carbonate and other dissolved minerals
Prohodna is a karst cave in north central Bulgaria, located in the Iskar Gorge near the village of Karlukovo in Lukovit Municipality, Lovech Province. The cave is known for the two holes in its ceiling, known as the Eyes of God or Oknata. Prohodna is the best known attraction in the Karlukovo Gorge, one of the largest karst regions in Bulgaria, formed during the Quaternary, Prohodna is 262 metres long, which makes it the longest cave passage in Bulgaria. The cave has two entrances which lie opposite one another, known respectively as the Small Entrance and the Big Entrance, the former is 35 metres high and the latter reaches 42.5 or 45 metres in height. The cave owes its name, which literally means Thoroughfare Cave or Passage Cave, the size of the Big Entrance of Prohodna makes it suitable for bungee jumping, and it is among the popular spots in Bulgaria for that activity. There are traces of habitation in the Prohodna cave, which testify that humans lived in the cave during the Neolithic and Chalcolithic.
Prohodna is most notable for the two equal-sized holes in the ceiling of its middle chamber, the holes, formed through erosion, let in light into the cave. The formation is known as the Eyes of God or Oknata. The phenomenon was featured in the 1988 Bulgarian film Time of Violence, in the scene, the cave lies 2 kilometres from Karlukovo, near the Karlukovo–Lukovit road. It is accessible from Rumyantsevo, and there is a lot near the Small Entrance. Near Prohodna is the much longer cave Temnata Dupka, and a pathway from the Big Entrance of Prohodna leads to the Petar Tranteev National Caving House, one of the 100 Tourist Sites of Bulgaria
Saeva dupka is a cave in northern Bulgaria near the village of Brestnitsa, Lovech Province. Its five halls and 400 metres of corridors offer some of the most beautiful cave formations in the country, the cave has hosted many choral music performances, thanks to the excellent acoustic conditions. Saeva dupka was named after two brothers and Sae, who used it as a place during the Ottoman occupation of Bulgaria. Recent excavations have shown the cave was inhabited since Roman times, saeva dupka is one of the 100 Tourist Sites of Bulgaria. Saeva dupka - The Kingdom of down-below, archived from the original on August 14,2007
Snezhanka is a show cave in the Rhodope Mountains, some 5 km away from the town of Peshtera, southern Bulgaria. To reach it requires a half an hour uphill, some of the most beautiful cave formations in Bulgaria can be seen inside. The cave is 145 metres long, with a constant annual temperature of 8°C, the cave is rich in stalactites, stalagmites and sinter lakes. It consists of several halls, Udders Hall, The Large Hall, The Music Hall. In the Wonderful Hall, built by snow-white crystal sinter, nature has shaped a figure, often likened to the fairy-tale character Snow White, in the middle of the cave there are circular hearths, where animal bones and artifacts dating back to early Iron Age were discovered. The Thracians used the cave as a refuge from their enemies, snezhanka is among the 100 National Touristic Places of the Bulgarian Touristic Union. The cave is open to visitors
Austria, officially the Republic of Austria, is a federal republic and a landlocked country of over 8.7 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north and Slovakia to the east and Italy to the south, the territory of Austria covers 83,879 km2. The terrain is mountainous, lying within the Alps, only 32% of the country is below 500 m. The majority of the population speaks local Bavarian dialects of German as their native language, other local official languages are Hungarian, Burgenland Croatian, and Slovene. The origins of modern-day Austria date back to the time of the Habsburg dynasty, from the time of the Reformation, many northern German princes, resenting the authority of the Emperor, used Protestantism as a flag of rebellion. Following Napoleons defeat, Prussia emerged as Austrias chief competitor for rule of a greater Germany, Austrias defeat by Prussia at the Battle of Königgrätz, during the Austro-Prussian War of 1866, cleared the way for Prussia to assert control over the rest of Germany.
In 1867, the empire was reformed into Austria-Hungary, Austria was thus the first to go to war in the July Crisis, which would ultimately escalate into World War I. The First Austrian Republic was established in 1919, in 1938 Nazi Germany annexed Austria in the Anschluss. This lasted until the end of World War II in 1945, after which Germany was occupied by the Allies, in 1955, the Austrian State Treaty re-established Austria as a sovereign state, ending the occupation. In the same year, the Austrian Parliament created the Declaration of Neutrality which declared that the Second Austrian Republic would become permanently neutral, Austria is a parliamentary representative democracy comprising nine federal states. The capital and largest city, with a population exceeding 1.7 million, is Vienna, other major urban areas of Austria include Graz, Linz and Innsbruck. Austria is one of the richest countries in the world, with a nominal per capita GDP of $43,724, the country has developed a high standard of living and in 2014 was ranked 21st in the world for its Human Development Index.
Austria has been a member of the United Nations since 1955, joined the European Union in 1995, Austria signed the Schengen Agreement in 1995, and adopted the euro currency in 1999. The German name for Austria, Österreich, meant eastern realm in Old High German, and is cognate with the word Ostarrîchi and this word is probably a translation of Medieval Latin Marchia orientalis into a local dialect. Austria was a prefecture of Bavaria created in 976, the word Austria is a Latinisation of the German name and was first recorded in the 12th century. Accordingly, Norig would essentially mean the same as Ostarrîchi and Österreich, the Celtic name was eventually Latinised to Noricum after the Romans conquered the area that encloses most of modern-day Austria, around 15 BC. Noricum became a Roman province in the mid-first century AD, heers hypothesis is not accepted by linguists. Settled in ancient times, the Central European land that is now Austria was occupied in pre-Roman times by various Celtic tribes, the Celtic kingdom of Noricum was claimed by the Roman Empire and made a province
Amphibians are ectothermic, tetrapod vertebrates of the class Amphibia. They inhabit a variety of habitats, with most species living within terrestrial, arboreal or freshwater aquatic ecosystems. Thus amphibians typically start out as larvae living in water, the young generally undergo metamorphosis from larva with gills to an adult air-breathing form with lungs. Amphibians use their skin as a respiratory surface and some small terrestrial salamanders and frogs lack lungs. They are superficially similar to lizards but, along with mammals and birds, reptiles are amniotes, the earliest amphibians evolved in the Devonian period from sarcopterygian fish with lungs and bony-limbed fins, features that were helpful in adapting to dry land. They diversified and became dominant during the Carboniferous and Permian periods, over time, amphibians shrank in size and decreased in diversity, leaving only the modern subclass Lissamphibia. The three modern orders of amphibians are Anura and Apoda, the number of known amphibian species is approximately 7,000, of which nearly 90% are frogs.
The smallest amphibian in the world is a frog from New Guinea with a length of just 7.7 mm. The largest living amphibian is the 1.8 m Chinese giant salamander, the study of amphibians is called batrachology, while the study of both reptiles and amphibians is called herpetology. The word amphibian is derived from the Ancient Greek term ἀμφίβιος, the term was initially used as a general adjective for animals that could live on land or in water, including seals and otters. Traditionally, the class Amphibia includes all tetrapod vertebrates that are not amniotes, the numbers of species cited above follows Frost and the total number of known amphibian species is over 7,000, of which nearly 90% are frogs. With the phylogenetic classification, the taxon Labyrinthodontia has been discarded as it is a group without unique defining features apart from shared primitive characteristics. Classification varies according to the phylogeny of the author and whether they use a stem-based or a node-based classification.
The phylogeny of Paleozoic amphibians is uncertain, and Lissamphibia may possibly fall within groups, like the Temnospondyli or the Lepospondyli. If the common ancestor of amphibians and amniotes is included in Amphibia, all modern amphibians are included in the subclass Lissamphibia, which is usually considered a clade, a group of species that have evolved from a common ancestor. The three modern orders are Anura and Gymnophiona, although the fossils of several older proto-frogs with primitive characteristics are known, the oldest true frog is Prosalirus bitis, from the Early Jurassic Kayenta Formation of Arizona. It is anatomically similar to modern frogs. The oldest known caecilian is another Early Jurassic species, Eocaecilia micropodia, the earliest salamander is Beiyanerpeton jianpingensis from the Late Jurassic of northeastern China
Ledenika is a cave in the Northwestern parts of the Balkan Mountains,16 km away from the Bulgarian city of Vratsa, its entrance being at 830m above sea level. It features an abundance of galleries and impressive karst formations including stalactites and stalagmites, the cave is about 300m long and contains ten separate halls. The biggest one is the Concert Hall, the way to it is through the Passage of Sinners. Only those whose heart is pure can pass through it, once the cave was full of water but now only a small lake has remained - the Lake of Wishes. The legend says if you dip your hand in the ice-cold water of the lake and make a wish. The first hall is the Antechamber, in winter and springtime this hall enchants with its ice crystal decoration that the cave is named after. For a few metres – through the Plaznyata Passage – you need to walk with head down – up until the tiny almost round hall –. Everything here is majestic and unique – the Crocodile, the Giant’s head, the Falcon, Santa Claus, from the big hall – through the iron bridge, the Big and Small Precipices and the Pelmets Passage – you arrive in the beautiful White Hall.
In here you can see the Mother-in-law’s Tongue, the Giant’s Wife, the Elephant, the highest point of the cave is called the Seventh Sky – accessible only to the most enthusiastic tourists. The temperature in the cave varies from –7°С to –15°С, not many animals can be seen other than bats, cave beetles, wood-lice and the unique “Ledenicus” or “Light-hater” insects. Little vegetation is adapted to the cave, only poorly developed lichens, the cave is part of the 100 Tourist Sites of Bulgaria, Bulgarian Tourist Union, Working hours - summer,8,30 to 12, 30am and 1,30 to 6, 00pm. Winter,8, 30am to 4, 00pm, seal available, Ledenika Peak on Graham Land in Antarctica is named after the cave. Amusement park Ledenika Caves in Bulgaria List of caves in Bulgaria
European tree frog
The European tree frog is a small tree frog found in Europe and part of Africa. Based on molecular genetic and other data, a number of taxa formerly treated as subspecies of H. arborea are now recognized as full species. European tree frogs are small, males range from 32–43 mm in length and they are slender, with long legs. Their dorsal skin is smooth, while their skin is granular. Their dorsal skin can be green, gray, or tan depending on the temperature and their ventral skin is a whitish color, and the dorsal and ventral skin is separated by a dark brown lateral stripe from the eyes to the groin. Females have white throats, while males have golden brown throats with large vocal sacs, the head of H. arborea is rounded, the lip drops strongly, the pupil has the shape of a horizontal ellipse, and the tympanum is clearly recognizable. The discs on the toes, which it uses to climb trees and hedges, is a characteristic feature of H. arborea. Like other frogs, their legs are much larger and stronger than the fore legs.
Members of the H. arborea species complex are the representatives of the widespread tree frog family indigenous to mainland Europe. And are found across most of Europe, northwest Africa, and it has been introduced to the United Kingdom, and it has been reintroduced to Latvia. European tree frogs can be found in marshlands, damp meadows, reed beds, gardens, orchards, stream banks, lakeshores, or humid or dry forests. They tend to avoid dark or thick forests, and they are able to tolerate some periods of dryness, historically, tree frogs were used as barometers because they respond to approaching rain by croaking. Depending on subspecies, temperature and the mood, skin colour ranges from bright to olive green, brown. European tree frogs eat a variety of arthropods, such as spiders, beetles, butterflies. Their ability to take long leaps allow them to catch fast-flying insects and they hibernate in walls, under rocks, under clumps of vegetation, or buried in leaf piles or manure piles. European tree frogs reproduce in stagnant bodies of water, such as lakes, swamps and they croak in the breeding season, even when migrating to their mating pools or ponds.
Males will often change breeding ponds, even within the breeding season. After a spring rain, the males will call females from low vegetation or shallow ponds, about 800 to 1000 eggs are laid in clumps the size of a walnut
Kozarnika or Peshtera Kozarnika is a cave in northwestern Bulgaria that was used as a hunters’ shelter as early as the Lower Paleolithic. It marks an older route of human migration from Africa to Europe via the Balkans. The cave probably keeps the earliest evidence of symbolic behaviour. Kozarnika cave is located 6 km from the town of Belogradchik in northwestern Bulgaria, on the slopes of the Balkan Mountains. It is opened to the south, at 85 m above the valley, with its length of 210 m, the cave is among the small-sized in the Belogradchick karst region. The Kozarnika cave project started in 1984, since 1996, it has been headed by Dr. Prof. Nikolay Sirakov and Dr. Jean-Luc Guadelli. In the ground layers, dated to 1. 6–1, the findings from Middle Paleolithic layers, rather bifacial points, dating from 300, 000–50,000 BP prove presence of hunters’ groups possibly of Homo neanderthalensis. Upper Paleolithic layers consist flint assemblages from the earliest European Gravette complex dating from 43,000 up to 39,000 BP belonging to Homo sapiens sapiens, magura Cave Bacho Kiro cave Sićevo Gorge Peștera cu Oase Vértesszőlős Proto-Indo-Europeans Campanian Ignimbrite Eruption Rincon, Paul
The Magura Cave is located in north-western Bulgaria close to the village of Rabisha,25 km from the town of Belogradchik in Vidin Province. Guided visits are conducted by the staff of Belogradchik municipality, to which the management of the cave was transferred in 2012 by the Bulgarian Council of Ministers, in 1984 the site was induced into UNESCOs tentative list of World Heritage. The total length of the 15 million year old cave is 2.5 km, the average annual temperature of the cave is 12 °C, except for one room where the temperature is always 15 °C. The air humidity reaches 80% and the displacement -56 m, the Magura cave was formed in the limestone Rabisha Hill. The morphology of the consists of one main gallery with six various-sized halls. The very spacious site allows for music concerts to be held during Christmas, the inner temperature is constantly 11-12 °C. During the summers of 1974 and 1975 the cave was used for speleotherapy. Thirty patients slept in the cave for twelve nights, taking advantage of allergens absence, constant humidity.
A part of the cave is now used for ageing sparkling and red wines, labelled Magura, bones from different prehistoric species like cave bear, cave hyena, wolf, wild cat and otter have been discovered in the Magura Cave. Today, constant inhabitants of the cave is the collembola, as well as four types of bats, Cave paintings dating from the Epipaleolithic, late Neolithic and early Bronze Age decorate some of the caves walls. The paintings have been estimated to be made between 10.000 and 8.000 years ago, the drawings represent important events of the society that had occupied the Magura cave, religious ceremonies, hunting scenes and depictions of deities which are unique on the Balkan peninsula. The Fertility Dance and the Hunting Ceremony rank among the most noteworthy paintings, one grouping from the Bronze Age has been interpreted as a solar calendar. The cave paintings allowed storing information about regional solar calendar, religious festivals, contemporary imitations of possible fertility rites are reported — inscriptions in Latin and paintings made by treasure-hunters.
The medium used to create the art was bat guano, more than 750 images have been identified. Painted signs can be organised into four groups, zoomorphic, geometric. For the first group, there are bitriangular silhouettes with raised rounded arms, ithyphallic figures, regarding zoomorpic items, there are caprids, dogs, ostrich-like animals and schematic linear quadrupeds. Few rayed circle figures, mainly the two unica of the so-called calendar scene, likely represent a sun depiction, taking count of some associated figures, it is possible to recognize dancing and mating scenes. In the so-called Cult Hall a large dance and hunting scene is depicted, arranged in two main rows, these are the best known and most reproduced Magura Cave images
Eurasian crag martin
The Eurasian crag martin or just crag martin is a small passerine bird in the swallow family. It is about 14 cm long with ash-brown upperparts and paler underparts, and it breeds in the mountains of southern Europe, northwestern Africa and southern Asia. It can be confused with the three species in its genus, but is larger than both, with brighter tail spots and different plumage tone. Many European birds are resident, but some populations and most Asian breeders are migratory, wintering in northern Africa. The Eurasian crag martin builds a nest adherent to the rock under an overhang or increasingly onto a man-made structure. It makes a neat half-cup mud nest with a soft lining of feathers. Nests are often solitary, although a few pairs may breed close together at good locations. Two to five brown-blotched white eggs are incubated mainly by the female and this species does not form large breeding colonies, but is gregarious outside the breeding season. It feeds on a variety of insects that are caught in its beak as the martin flies near to cliff faces or over streams.
Adults and young may be hunted and eaten by birds of prey or corvids, with its very large and expanding range and large population there are no significant conservation concerns. Its nearest relatives are the three members of the genus, the pale crag martin, P. obsoleta, the rock martin, P. fuligula. The genus name is derived from the Greek ptuon, a fan, referring to the shape of the tail, and Procne. The specific rupestris means of rocks, from the Latin rupes rock, there are no generally recognised subspecies. Fossils of this species have found in Late Pleistocene deposits in Bulgaria. DNA studies suggest that there are three groupings within the Hirundininae, broadly correlating with the type of nest built. The groups are the core martins including burrowing species like the sand martin, the nest-adopters, which are birds like the tree swallow that utilise natural cavities, and the mud nest builders. The Eurasian crag martin is 13–15 cm long with a 32–34.5 cm wingspan and it has ash-brown upperparts and paler underparts, and has a broader body and tail than any other European swallow.
The tail is short and square, with white patches near the tips of all but the central, the underwing and undertail coverts are blackish, the eyes are brown, the small bill is mainly black, and the legs are brownish-pink
The Areni-1 cave complex is located near the Areni village in southern Armenia along the Arpa River. In 2010, it was announced that the earliest known shoe was found at the site, in January 2011, the earliest known winery in the world was announced to have been found. Also in 2011, the discovery of a straw skirt dating to 3900 BC was reported, in 2009, the oldest brain was discovered