The Borra Caves (also called ''Borra Guhalu'') are located on the East Coast of India, in the Ananthagiri hills of the

Araku Valley Araku Valley is a hill station in Alluri Sitharama Raju district in the Indian state of Andhra Pradesh, lying 111 km west of Visakhapatnam city. This place is often referred to as ''Ooty of Andhra''. It is a valley in the Eastern Ghats inh ...

(with hill ranges' elevation varying from ) of the Alluri Sitharama Raju district in

Andhra Pradesh Andhra Pradesh (, abbr. AP) is a state in the south-eastern coastal region of India. It is the seventh-largest state by area covering an area of and tenth-most populous state with 49,386,799 inhabitants. It is bordered by Telangana to the ...

. The caves, one of the largest in the country, at an elevation of about , distinctly exhibit a variety of

speleothems A speleothem (; ) is a geological formation by mineral deposits that accumulate over time in natural caves. Speleothems most commonly form in calcareous caves due to carbonate dissolution reactions. They can take a variety of forms, depending on ...

ranging in size and irregularly shaped stalactites and

stalagmites A stalagmite (, ; from the Greek , from , "dropping, trickling") is a type of rock formation that rises from the floor of a cave due to the accumulation of material deposited on the floor from ceiling drippings. Stalagmites are typically co ...

. The caves are basically

karstic Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant ro ...

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

structures extending to a depth of , and are considered the deepest caves in India. :File:Borra Caves Info board.JPG

History

The native name for the caves is ''Borra Guhalu''. Where ''Borra'' means abdomen in

Telugu language Telugu (; , ) is a Dravidian language spoken by Telugu people predominantly living in the Indian states of Andhra Pradesh and Telangana, where it is also the official language. It is the most widely spoken member of the Dravidian language fam ...

and ''guhalu'' means caves in

Etymology

The name Borra'' came from an Desia Odia word 'Bora', which means "a hole", as the district shares its Long border line with Odisha, hence the name comes.

Legend

On the discovery of the caves, there are several legends, which the tribals (Jatapu, Porja, Kondadora, Nookadora, valmiki etc.) who inhabit the villages around the caves narrate. The popular legend is that a cow, grazing on the top of the caves, dropped through a hole in the roof. The cowherd while searching for the cow came across the caves. He found a stone inside the cave that resembled a

Lingam A lingam ( sa, लिङ्ग , lit. "sign, symbol or mark"), sometimes referred to as linga or Shiva linga, is an abstract or aniconic representation of the Hindu god Shiva in Shaivism. It is typically the primary '' murti'' or devotional ...

, which he interpreted as the Lord

Shiva Shiva (; sa, शिव, lit=The Auspicious One, Śiva ), also known as Mahadeva (; ɐɦaːd̪eːʋɐ, or Hara, is one of the principal deities of Hinduism. He is the Supreme Being in Shaivism, one of the major traditions within Hindu ...

who protected the cow. The village folk who heard the story believed it and since then they have built a small temple for Lord Shiva outside the cave. People flock to the temple for worship and the cave to get a glimpse of the Lingam. Borra Caves Lingam

Another lyrical legend is that the

representing the

Hindu Hindus (; ) are people who religiously adhere to Hinduism. Jeffery D. Long (2007), A Vision for Hinduism, IB Tauris, , pages 35–37 Historically, the term has also been used as a geographical, cultural, and later religious identifier for ...

God Lord

, is found deep in the caves and above which is a stone formation of a cow (

Sanskrit Sanskrit (; attributively , ; nominally , , ) is a classical language belonging to the Indo-Aryan branch of the Indo-European languages. It arose in South Asia after its predecessor languages had diffused there from the northwest in the late ...

Kamadhenu Kamadhenu ( sa, कामधेनु, , ), also known as Surabhi (, or , ), is a divine bovine-goddess described in Hinduism as the mother of all cows. She is a miraculous cow of plenty who provides her owner whatever he desires and is often ...

). It is surmised that the udder of this cow is the source of the Gosthani (Sanskrit: Cow's udder) River which originates from here, flows through

Vizianagram Vizianagaram is a city and the headquarters of Vizianagaram district in the Indian state of Andhra Pradesh. It is central Eastern Ghats, about west of the Bay of Bengal and north-northeast of Visakhapatnam. The city has a population of 228,02 ...

and

Visakhapatnam , image_alt = , image_caption = From top, left to right: Visakhapatnam aerial view, Vizag seaport, Simhachalam Temple, Aerial view of Rushikonda Beach, Beach road, Novotel Visakhapatnam, INS Kursura submarine museu ...

districts before emptying into the

Bay of Bengal The Bay of Bengal is the northeastern part of the Indian Ocean, bounded on the west and northwest by India, on the north by Bangladesh, and on the east by Myanmar and the Andaman and Nicobar Islands of India. Its southern limit is a line betwee ...

near Bheemunipatnam. Valley Borracaves Eastern Ghats Visakhapatnam

Geography and climate

The caves are located in the

of the Ananthagiri hill range and is drained by the

Gosthani River The Gosthani rises in the Ananthagiri Hills of the Eastern Ghats and flows through the Borra Caves which lie near its source. It is the largest river flowing through Visakhapatnam city. It flows for 120 km before joining the Bay of Bengal ...

. At the entry, the cave measures up to horizontally and vertically. Stalagmite and stalactite formations are found in the caves. The average annual

temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measurement, measured with a thermometer. Thermometers are calibrated in various Conversion of units of temperature, temp ...

of Araku hills, where the caves are situated, is about . The average annual

rainfall Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water f ...

reported is (mostly occurring during the northeast

monsoon A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with annual latitudinal osci ...

). The Gosthani river provides water supply to the

city.

Geology

The regional geology in the

Eastern Ghats The Eastern Ghats are a discontinuous range of mountains along India's eastern coast. The Eastern Ghats pass through Odisha, Andhra Pradesh to Tamil Nadu in the south passing some parts of Karnataka as well as Telangana. They are eroded and cut ...

mobile belt, where the caves are located, is represented by the

khondalite Khondalite is a Foliation (geology), foliated metamorphic rock. In India, it is also called ''Bezwada Gneiss'' and ''Kailasa Gneiss''. It was named after the Khonds, Khond tribe of Odisha and Andhra Pradesh because well-formed examples of the ...

suite of rocks (garnetiferrous

sillimanite Sillimanite is an aluminosilicate mineral with the chemical formula Al2SiO5. Sillimanite is named after the American chemist Benjamin Silliman (1779–1864). It was first described in 1824 for an occurrence in Chester, Connecticut. Occurrence ...

gneisses Gneiss ( ) is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. Gneiss forms at higher temperatures an ...

quartz Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical ...

o-feldsphatic

garnet Garnets () are a group of silicate minerals that have been used since the Bronze Age as gemstones and abrasives. All species of garnets possess similar physical properties and crystal forms, but differ in chemical composition. The different s ...

) of Archaen age. Quaternary deposits consist of red bed

sediments Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity In physics, gravity () is a fundame ...

, laterites, pediment fans,

colluvium Colluvium (also colluvial material or colluvial soil) is a general name for loose, unconsolidated sediments that have been deposited at the base of hillslopes by either rainwash, sheetwash, slow continuous downslope creep, or a variable combinati ...

alluvium Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. ...

and

coastal The coast, also known as the coastline or seashore, is defined as the area where land meets the ocean, or as a line that forms the boundary between the land and the coastline. The Earth has around of coastline. Coasts are important zones in ...

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class o ...

s. The caves in the reserved forest area basically host a variety of

of various sizes and irregularly shaped stalactites and stalagmites. The

carbonate rock Carbonate rocks are a class of sedimentary rocks composed primarily of carbonate minerals. The two major types are limestone, which is composed of calcite or aragonite (different crystal forms of CaCO3), and dolomite rock (also known as dolosto ...

s are pure white, and coarsely

crystalline A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...

and the deformed and banded

marble Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite. Marble is typically not foliated (layered), although there are exceptions. In geology, the term ''marble'' refers to metamorphose ...

s cover a triangular area of ; surrounded by

diopside Diopside is a monoclinic pyroxene mineral with composition . It forms complete solid solution series with hedenbergite () and augite, and partial solid solutions with orthopyroxene and pigeonite. It forms variably colored, but typically dull ...

–

scapolite The scapolites (Gr. σκάπος, rod, and λίθος, stone) are a group of rock-forming silicate minerals composed of aluminium, calcium, and sodium silicate with chlorine, carbonate and sulfate. The two endmembers are meionite () and marialit ...

–

feldspar Feldspars are a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the ''plagioclase'' (sodium-calcium) felds ...

calc-granulites. The

pyroxenite Pyroxenite is an ultramafic igneous rock consisting essentially of minerals of the pyroxene group, such as augite, diopside, hypersthene, bronzite or enstatite. Pyroxenites are classified into clinopyroxenites, orthopyroxenites, and the we ...

outcrops are dark and massive and include discontinuous calc-silicate bands, some of brown mica and others with calcite.

Formation

The

, which originates from these caves and flows between the solidified stalactites and stalagmites in the karstic limestones formation, is the cause for the development of the odd shapes of structures. Water percolating from the roof of the caves dissolve

and trickle drop by drop to form stalactites at the roof of the cave and then dripping down to the ground form stalagmites. These deposits have developed into interesting forms and structures inside the caves such as Shiva–Parvati, Mother–Child, Rishi's beard, human brain, mushrooms, crocodile, temple, church, etc. These shapes have captured the imagination of tourists, while some have been given religious interpretations.

Formations in the caves

The caves are deep and totally

aphotic The aphotic zone (aphotic from Greek prefix + "without light") is the portion of a lake or ocean where there is little or no sunlight. It is formally defined as the depths beyond which less than 1 percent of sunlight penetrates. Above the aphot ...

. There is an area in the caves with limited light penetration. The stalactites seen in the caves are about in length while the stalagmites are long and columns are in height and in width. The height of the cave is and the length is about . The average temperature of the inner cave wall is reported to be about . Sulfur springs discharge into the cave passages causing

corrosion Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engi ...

of limestone. The spring waters display floating

mucus Mucus ( ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both serous and mucous cells. It ...

-like

biofilms A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular po ...

. These are thick orange microbial mats ( thick) with patches of yellow biofilms extending from the aphotic deep cave orifice. While the caves are basically limestone formations, the area surrounding these are of mica formations which are prospected for precious stones like rubies. Archeological artifacts ( Paleolithic implements) have been found in the caves. The excavations carried out in the caves by the archeologists of the Andhra University, have unearthed stone tools of middle Paleolithic culture dating back 30,000 to 50,000 years, which confirm human habitation.

Genesis

Speleothem A speleothem (; ) is a geological formation by mineral deposits that accumulate over time in natural caves. Speleothems most commonly form in calcareous caves due to carbonate dissolution reactions. They can take a variety of forms, depending ...

carbonates A carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word ''carbonate'' may also refer to a carbonate ester, an organic compound containing the carbonate g ...

found in the caves have been subject to scientific studies. In fluviatile, spring, cave and soil environments microbial carbonates are important. In the biofilms and/or microbial mats, which are formed in the caves, the principal organisms associated are

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...

, particularly cyanobacteria, small algae and

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...

Petrographic Petrography is a branch of petrology that focuses on detailed descriptions of rocks. Someone who studies petrography is called a petrographer. The mineral content and the textural relationships within the rock are described in detail. The class ...

analysis of a

thin section In optical mineralogy and petrography, a thin section (or petrographic thin section) is a thin slice of a rock or mineral sample, prepared in a laboratory, for use with a polarizing petrographic microscope, electron microscope and electron ...

has uncovered the presence of

lithified Lithification (from the Ancient Greek word ''lithos'' meaning 'rock' and the Latin-derived suffix ''-ific'') is the process in which sediments compact under pressure, expel connate fluids, and gradually become solid rock. Essentially, lithificatio ...

structures and

micrite Micrite is a limestone constituent formed of calcareous particles ranging in diameter up to four μm formed by the recrystallization of lime mud. Flügel, Erik, ''Microfacies of Carbonate Rocks: Analysis, Interpretation and Application,'' Springe ...

, present as laminated to clotted with chocolate-brown blebs. These are identical to microbialites observed in modern and ancient stromatolitic carbonates. Laboratory observations with scanning electron microscope (SEM) have also confirmed the presence of calcified bacteria, micro-rods, and needle calcite. Organic mats (yellow-orange in colour) are made up of mineralized filamentous bacteria, bacterial stalks, cells and sheaths. Thus, these studies have indicated that

microorganism A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in olde ...

s have actively influenced the genesis of speleothems of the Borra Caves.

Biological environment

Micro organisms

The effect of microorganisms in the mats on the cave formation and their role on iron mineral precipitation has been further studied. A report indicates a link between iron–rich mats formation and iron precipitating bacteria.

Fauna and flora

The

fauna Fauna is all of the animal life present in a particular region or time. The corresponding term for plants is ''flora'', and for fungi, it is ''funga''. Flora, fauna, funga and other forms of life are collectively referred to as ''Biota (ecology ...

observed in the caves are predominantly bats, as well as the

golden gecko The golden gecko (''Gekko badenii''), also known commonly as Baden's Pacific gecko, is a species of lizard in the family Gekkonidae. The species is native to Vietnam. Etymology The specific name, ''badenii'', refers to '' Núi Bà Đen'' (Bla ...

. The type of bat reported is the fulvous fruit bat ('' Rousettus leschenaultii'') – a species which roosts in large caves, old buildings, dungeons and dark areas of old forts. This species has short and slender musculature with large, well developed eyes. They feed on

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

s and

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...

s, particularly

jamun ''Syzygium cumini'', commonly known as Malabar plum, Java plum, black plum, jamun, jaman, jambul, or jambolan, is an evergreen tropical tree in the flowering plant family Myrtaceae, and favored for its fruit, timber, and ornamental value. It is ...

, guava,

silk Silk is a natural protein fiber, some forms of which can be woven into textiles. The protein fiber of silk is composed mainly of fibroin and is produced by certain insect larvae to form cocoons. The best-known silk is obtained from the ...

cotton Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus '' Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor pe ...

and mango.

Stygofauna

''Habrobathynella borraensis'' was described from the Borra Caves. It is the first Indian cavernicolous species of the genus ''Habrobathynella''.

Location and access

The caves are located in the Ananthagiri hills range of the

Araku valley Araku Valley is a hill station in Alluri Sitharama Raju district in the Indian state of Andhra Pradesh, lying 111 km west of Visakhapatnam city. This place is often referred to as ''Ooty of Andhra''. It is a valley in the Eastern Ghats inh ...

of the Alluri Sitharama Raju district in

. The caves are from Bhubaneshwar in

Odisha Odisha (English: , ), formerly Orissa ( the official name until 2011), is an Indian state located in Eastern India. It is the 8th largest state by area, and the 11th largest by population. The state has the third largest population of ...

and from

Hyderabad Hyderabad ( ; , ) is the capital and largest city of the Indian state of Telangana and the ''de jure'' capital of Andhra Pradesh. It occupies on the Deccan Plateau along the banks of the Musi River, in the northern part of Southern India ...

, both via National Highway 5. The caves are well connected by

road A road is a linear way for the conveyance of traffic that mostly has an improved surface for use by vehicles (motorized and non-motorized) and pedestrians. Unlike streets, the main function of roads is transportation. There are many types of ...

rail Rail or rails may refer to: Rail transport *Rail transport and related matters *Rail (rail transport) or railway lines, the running surface of a railway Arts and media Film * ''Rails'' (film), a 1929 Italian film by Mario Camerini * ''Rail'' ( ...

and air services. The nearest international airport is

Visakhapatnam Airport Visakhapatnam Airport is a customs airport in Visakhapatnam, Andhra Pradesh, India. It also operates as a civil enclave on an Indian Navy airbase named INS ''Dega''. It lies between the city localities of NAD X Road and Gajuwaka. The airpor ...

, from Borra Caves, which is from the

city center. Vishkapatnam is away by road. It is mostly a hill road and the journey takes about three hours. Train services operate on the

Kothavalasa Kothavalasa is a Suburb in Visakhapatnam city but present in Vizianagaram district of the Indian state of Andhra Pradesh. It is located in Kothavalasa mandal of Vizianagaram revenue division. It is located 30 km from the city of Visakhap ...

Kirandul Kirandul is a town and a municipality in Dantewada district in the Indian state of Chhattisgarh. It is located roughly 400 km south of Raipur, capital of Chhattisgarh and 41 km southwest of Dantewada-the district headquarters. The wa ...

railway line in

East Coast Railway The East Coast Railway (abbreviated ECoR) is one of the 19 railway zones of Indian Railways. It came into existence on 1 April 2003. The headquarters of the zone are at Bhubaneswar, Odisha History Consequent upon the parliament's approval, Ea ...

Indian Railways Indian Railways (IR) is a statutory body under the ownership of Ministry of Railways, Government of India that operates India's national railway system. It manages the fourth largest national railway system in the world by size, with a tota ...

. The train journey over a distance of from the Vishkapatanam railway station passes through Eastern Ghats (hill) section), which has 30 tunnels en route. The journey by train takes about five hours to the Railway Station near the caves called the Borra Guhalu Railway station.

Visitor information

Guided tours for a day trip to the Borra Caves cover interesting attractions like the Tyada Railway Tunnel, Damuku View Point, Ananthagiri

Coffee Coffee is a drink prepared from roasted coffee beans. Darkly colored, bitter, and slightly acidic, coffee has a stimulating effect on humans, primarily due to its caffeine content. It is the most popular hot drink in the world. Seeds of ...

Plantation A plantation is an agricultural estate, generally centered on a plantation house, meant for farming that specializes in cash crops, usually mainly planted with a single crop, with perhaps ancillary areas for vegetables for eating and so on. The ...

, Padmapuram Gardens and the Araku Valley. For the benefit of the visitors, an information board at the entry point to the caves gives some details of the caves and its surroundings (pictured). An Arraku and Borra rail-cum-road package tour organized by the

Andhra Pradesh State Tourism Department The Andhra Pradesh Tourism Development Corporation (APTDC) is a state government agency which promotes tourism in Andhra Pradesh, India. The department offers tour packages of Heritage, Nature, Adventure, Health and Rural tourism representing r ...

is available for visitors keen to see the Borra Caves. A walk around the caves provides views of the mountainous area which is rich in flora and fauna. The Andhra Pradesh State Tourism Department has installed 26 mercury, sodium vapor and halogen electric lamps, which provide views of the formations. The Araku valley, a hill station about from the Borra Caves, is also a tourist attraction for people visiting the caves. November and December are ideal months to visit the caves.

References

*Ramesh Y (1990). Geomorphic Studies in Upper Gostani River Basin with Special References to Borra (Karst) Caves Visakhapatnam District, A.P., India, India. *Le Bas, M.J., Subbarao, K.V. and Walsh, J.W. Metacarbonatite or marble? – the case of the carbonate, pyroxenite, calcite-apatite rock complex at Borra, Eastern Ghats, India, ''Journal of Asian Earth Sciences'', 20, 2002, 127–140.

External links

{{Commons category, Borra Caves
Borra Caves
Caves of Andhra Pradesh Geology of Andhra Pradesh Show caves in India