Mar 20, 2017 CANADA (SUN) A study of famous caves in ancient Bharat -- Part One.
The caves in prehistoric times, discovered all over the world, mostly represent natural caves partly improved by human hand. Some of them contain ante-chambers and the walls of many of them are decorated with pictures of animals and natural objects. These caves served as shelters of men in life and death. It was in them that our remote ancestors developed in different ways our culture and civilization.
The caves as religious retreats are referred to for the first time in the early texts of Buddhism. The cave (guha) of the Upanisads is not a religious retreat, but the cavity of the heart. The forests, open spaces, roads, tree-shades, deserted houses, cemeteries and mountain caves (giriguha) became important as temporary shelters and retreats of the Indian 'runaways' -- the recluses and wanderers, as distinguished from the hermits (tapasas). The caves also served as suitable places for meditation of the recluses. They were really the means of protection against heat and cold, wind and sunlight, ferocious animals and showers of rain. 
The early caves and caverns are mostly associated with the hills around the ancient city of Rajagriha. Only one of them is located in the neighbourhood of Kausambi. The Indrasila-guha and the Saptaparni cave are the most noted among the caves and caverns of Rajagriha. According to the Vinayapitaka, a natural cave deserves to be called a lena when it is touched by human hand and improved by human skill.
It is difficult to take the early caves to be the examples of cave architecture. The Indian caves acquired an architectural significance from the days of Asoka. They continued to be so up till the reign of King Kharavela of Orissa.
The four caves dedicated by Asoka to the Ajivikas in the Khalatika or Barabar hills, about 20 miles north of the town of Gaya, the three caves dedicated by Dasaratha in the Nagarjuni hills, and the caves dedicated to the Jain recluses on the twin hills of Udayagiri and Khandagiri were all intended to serve as shelters during the rains, while some of them in South India came to serve the sepulchral purpose in mediaeval times.
From the time of the Satakarnis of the Andhra dynasty, the Indian caves began to develop as viharas (monastic abodes) and caitayas, or shrines. This observation holds true of the caves of Karle, Bhaja, Ajanta, Ellora, Aurangabad, Elephanta and Bagh. The Kailasa temple of Ellora was a magnificent rock-cut temple which developed in the tradition of the caves as religious shrines.
As compared and contrasted with the caves of India, the lenas of Ceylon, which do not strictly deserve the name of guha, are nothing but the slanting slopes of rocks barely touched and rudely dressed by human hand.
Among the important Indian caves is Indasalaguha. As explained by Buddhaghosa  this cave took its name from an Indasala tree marking its entrance. The cave with this tree is represented in one of the Barhut sculptures. Later it also became known by the name of Indrasailaguha, evidently for the reason that it is made the scene of action of the famous Pali discourse called Sakkapanha Sutta -- the discourse in which Sakka or Inda, the king of the gods, interviewed the Buddha to have satisfactory replies to his questions.
In the Digha Nikaya we find that this cave is located in the Vediyaka mountain situated at a short distance to the north of the village of Ambasanda (Mango-grove).  The Vediyaka mountain is now identified with the Giriyak Hill, six miles from the city of Rajagaha, modern Rajgir. According to Buddhaghosa, it was a pre-existing cave between two hills with an Indrasala tree at its door. The particular hill with which it was connected was called Vediyaka or Vediya, since it was surrounded by altar-shaped blue rocks. 
We read in the Pali text that at the time when the Buddha stepped into it, the cave which was uneven became even, which was narrow became wide, and which was dark became lighted as if by the supernatural power of the gods…
The Barhut medallion represents it as a mountain cave with a rocky floor and open-mouthed hall inside having an arched roof. It is polished inside. The Indrasala tree is shown above it. The monkeys sit on cubicle rocks, while two bears peep out through the piled up rocks. 
On the Bodh-Gaya stone railings the cave has an open mouth and an arched hall inside, and it is enclosed by a Buddhist railing. It is difficult to infer from the description given in the Pali text that the cave received any improvement by human hand.
Varaha guha was a natural cave (sukarakhata) on the Gijjhakuta mountain, which served as a retreat to the wandering ascetics, including the Buddhist recluses. The wanderer named Dighanakha met the Buddha in this cave. It came to be known as the boar's cave evidently for the reason that it was a place for the boars to live in.
The Kandaras were all natural caverns in the rocks. The Tinduka Kandara was marked out by a Tinduka tree standing near it. The Tapoda kandara received its name from its proximity to the Tapodas or hot springs. Why Gomata Kandara was so called is not known. The Kapota Kandara was undoubtedly a favourite resort of the pigeons. The Udana locates it at some distance from Rajagaha while Hiuen Tsang places it about 9 or 10 miles north-east of the Indrasila cave.
Ajivika ('living', in Sanskrit) was a system of ancient Indian philosophy and an ascetic movement during the Mahajanapada period in the Indian subcontinent. Ajivika was primarily a heterodox Nastika system, mostly followed by wandering ascetics (shramanas or sannyasins).
The Ajivika movement reached its pinnacle during the rule of Mauryan emperor Bindusara, around the 4th Century B.C. Several famous rock-cut caves at Barabar Caves, Jehanabad district, Bihar, belonged to this sect. They were built during the times of the Mauryan emperor Ashoka (273 to 232 B.C.)