Abstract
The long and eventful history of the Nilgiris dates back to the remote Stone age or Prehistoric times. Prehistoric man appears to have lived in many parts of the Nilgiris District, especially on the eastern slopes. It is plausible that some of the Nilgiris tribes first occupied the region around this time or a bit later. Remains of Prehistoric rock paintings have been discovered in many sites the most important being the one at porivarai near karikkiyur. More areas of the district appear to have under human habitation during the Iron Age or the Megalithic Age that extends from around 1000 B.C, to 400 B.C., and slightly later. Different types of Megalithic graves have been discovered in many places including on the outskirts of Ooty and at anaikatti in the sigur forest range near the Anaikatti check post.

Introduction
The Nilgiri is situated 11 degrees north of the equator, and forms part of the Western Ghats complex. Many of the highest peaks in south India are found in the Upper Nilgiris. The indigenous groups –  Todas and Kotas on the higher reaches, along with Kurumbas and Irulas on the slopes have occupied the Nilgiris since ancient times. There are a number of prehistoric sites scattered throughout the hills that could be related to one or more of the indigenous peoples, or perhaps to another, previously existing groups that has now become extinct. These prehistoric sites comprise stone and earthen circles, cists, dolmens, shrines, and rock art.

Stone circle    
The prehistoric stone circle funerary sites on so many hilltops. These circular cairns are associated with the Toda people, the ones on mount mupoof, cists or burial chambers are usually rectangular or square, and unlike the circular caims, have their stones covering the entire structure. On the upper nilgiris plateau cists are much rarer than circles. Some circles that have an additional inner ring of vertical stones. The practice of building a stone circle around funerary sites began in ancient Dravidian societies, as a method of restraining certain malicious spirits of the dead from causing calamities such as famines and epidemics on a nearby village. The practice of construction stone circles around graves disappeared long age, but the Todas traditionally used stone wall enclosures for ashes at second funeral rites.

Snake stones
The three large stones that todas call Pob karsh, “Snake Stones” located in different parts of the Nilgiris. The ‘tail’ is located near Polodrykaihhrr hamlet, the middle portion can be seen in the vicinity of Teihhfakh hamlet and the ‘head’ portion can be found some distance away in the vicinity of Tarshawdr tee.

The head portion of the snake stone
Robber Stone    
A natural feature with an associated mythology is the Kollnngash, ‘The Robber Stone’ located near the Kota village of Tiruchbigadi. A Toda man from Teihhfakh to Paihhdrkash he shivered in fear, dropped the stone and ran back to his own settlement. The stone still remains where the paihhdrkash clansman is said to have dropped it. It is called the robber stone because, some todas say the paihhdrkash clansman stole it, others say the stone which moves only in the darkness of new moon nights, can never be seen, just like a thief in action. Todas, Kotas and Tamils who now live in this area all believe in the supernatural powers of this stone, vouching for the fact that it does indeed turn over on new moon nights.

Dolmens or Cromlechs
Badagas of the hills call these cromlech of dolmens as silakallu or sculptured stones and the kurumbas and the irulas call them as bira-kallu or hero stones. The dolmens or stone tables of upright stones with a cap stone resting on them 18 to 22 inches high are believed to have been built by a race of pandava dwarfs, who were nevertheless able to lift the huge stones with ease. The dolmens on the Nilgiris are supposed to have been made by a race of pygmies, assisted by hares and porcupines.the dolmens are found on the lower levels and near the passes which lead to low lands. Some Archaeologists also confirm that the dolmens are not burial places. The object found in them are quite different from the contents of the cairns and almost certainly more morden. The biggest dolmen is found in jackaneri a hamlet of kothagiri. The groups of sulptured dolmens are still found in Melur, Jakatala, Kamba, Sholur, Hlairu, Kodanad, Kakusi, Kateri, Melkundha and other places.

Cave Paintings
Pre-historic cave paintings have been discovered in the district in a place near Sigur. The paintings include depiction of an elephant lifting its tusk and before it is a buxom man. A tiger also has been drawn and a man is mounted on this tiger. Other figures drawn are a peacock, a monkey and a man holding the harness of a horse. Some other cave paintings have been found in Konavakkarai near Kothagiri of the district. The drawing include a ghose-like figure surrounded by men with swords and shields in their hands, a cat, a few male figures and a buffalo with her calf suckling her. The salient features of these cave paintings are the drawing in red colour of stag and a skeleton like figure. Some figures of deer have been painted in white colour and these paintings have been drawn using a white mixture. In the same village on a rock, some markings have been discovered. The marking are in the form of human figures, plants, creepers, trees, bent-squares, rectangles and animals.

Conclusion
Archaeologically the Nilgiris possesses innumerable pre-historic remains unique in themselves.Paleolithic and Neolithic civilizations had flourished on the hills for which there are ample evidences. There is no evidence for people having living on the upper nilgiris before christ ans most of the prehistoric remains were probably constructed between A.D.100 and 1100. In the case of dolmens and other remains.

R. Dhanish Fathima

Research Supervisor, Head and Associate Professor, PG and Research Dept of History, C.Abdul Hakeem College, Melvisharam, Vellore Dt.

Dr. H. Munavarjan

Ph.D Research Scholar, Bharathiyar Unirversity, Coimbatore.

References
1.    Dr.Sethuraman Suresh – A Guide to the Build Heritage of Ooty- Coonoor. 2016
2.    Dr.Tarun Chhabra – The Toda landscape Explorations in Cultural Ecology. 2015
3.    The Nilgiri District Gazetteers.
4.    Wall House M.J. – Archaeological Reminiscence.