Borra Caves is the deepest and one of the longest cave in India, it is also a popular tourist destination in Araku Valley of Andhra Pradesh. Situated within the green valley of Anantagiri hill with the view of the Gosthani river, this natural splendour seems to be opening to the underworld – a dark, wide-open mouth to swallow the people queuing into it. Is this the real dark dungeon of hell or an intriguing artwork of nature? Read on to know more.
The local name of these caves is Borra (meaning hole in Odia language) Guhalu (meaning cave in the Telugu language). It is tough to believe that such a huge cave lies beneath the green surrounding. The naturally formed cave is more than 150 million years old. It was officially discovered by the British geologist William King in the year 1807 although there are many tribal legends associated with the cave claiming the knowledge of its presence long before.
The entrance of the cave is situated at an altitude of 705 meters while the deepest point goes down to 625 meters. The total length of the cave is approximately 200 meters but the total walkway to trek within is 350 meters. The entry of the cave is huge (measuring 100 mt horizontally and 75 mt vertically) resembling a monster’s open mouth passing straight to its deep fat belly.
The Borra Caves is situated within the reserve forest area. The DBK (Dandakaranya-Bolangiri, Kibur) railway track runs above the cave. The spectacular green surrounding drained by the meandering Gosthani river is a feast to the eye. The train ride through this track is definitely a memorable experience and pleasure for the nature lovers.
Coming back to the Borra Caves, these caves are karstic limestone structures. Karst is a topography formed by dissolved soluble minerals of rock like limestone, dolomite and gypsum. Small to medium stream from the hill slopes flows to join the Gosthani (‘Go’ means Cow and ‘Sthane’ means udder) River through the cave. The humic acid in the water of the streams dissolves the minerals and reacts with the Calcium Carbonate of the limestone rocks of the topography.
This perennial flow of water since ages has carved out this deep natural wonder known as the Borra Caves. As the water drips through the roof of the cave the Calcium bicarbonate and other minerals in the rock dissolves in different degree to form heaps of various structures on the ground called “Stalagmites” and formed in the same way the pointed or protruding structures hanging from the roof are called “Stalactites”.
The discharge of the sulphur springs leads to corrosion and a floating yellow biofilm on the flowing water. Biofilms are thick yellowish orange microbial mat. Thus this speleothem or the cave formations have a considerable amount of microbial life.
The Stalactites and the Stalagmites take various shapes and structures and thus feed the human imagination to visualize them as Shivling, Shiv Parvati, mother and child, the human brain, tiger, crocodile, Cow’s udder, Sage’s beard and many other imaginative structures. The central part of the cave is the brain shaped stalagmite which is a wondrous creation of nature.
The caves are completely aphotic, so they have limited to no light entering the caves. The Andhra Pradesh State Tourism Department has installed mercury, sodium vapour and halogen electric lamps of multi colour to accentuate the structures within the cave and thus creating an uncanny atmosphere within.
There are certain completely dark areas within the cave which provides an ideal habitat for the bats. The acrid smell of guano marks the presence of the bats from a distance and passing through the area becomes tough for those who are sensitive to the sharp smells. The dark, humid and a moderate temperature within the caves provide the optimum condition for the grown and survival of many microorganisms, while other faunal lives found here are gecko and bats.
The stairs and the walkways constructed by the tourism department of Andhra Pradesh provides and easy accessibility to every area of the cave. The dark, humid atmosphere within the cave may make the climb little uncomfortable for some but the wide opening within the cave may not give you the claustrophobic feeling.
The Ananthagiri Hills and the Araku Valley area is home to Jatapu, Porja, Kondadora, Nookadora, Valmiki and some other tribal groups. Archaeological excavations have unearthed stone tools of middle Paleolithic age suggesting human habitation in the caves since the early ages of civilization.
Various structures formed by the stalactites and the stalagmites resemble shapes of gods and goddess. Thus certain areas have been demarcated as places of worship by the locals. On the Hindu annual festival of ‘Shivratri’ numerous devotees mostly the tribal inhabitants gather here to offer special prayers to the naturally formed Shiva Lingam within the caves.
The Borra Caves being one of the largest caves in India also holds great geological, religious, archaeological and ecological significance. Apart from its significance, it is also a natural wonder nested within the breathtaking hilly terrain. The journey to the caves through the evergreen moist deciduous forest is a treat to the eyes and soul and also a beautiful experience to endure.