Pre-history of Kerala
The first set of people of Kerala,can be identified only with reference to their burial practices. Several Mesolithic and Neolithic sites have been discovered though very little has been done by way of archaeological work and exploration. These people constructed burial monuments (between 10th century B.C. and 5th century A.D.) in granite, literate and pottery, most of which are strikingly similar to the megalithic monuments of West Europe and Asia. Rock paintings, engravings, and megalithic structures including dolmens, cists, rock-cut caves, thopikallu, pulachikallu, kudakkallu etc., have been discovered at numerous places in and around Edakkal and Marayur in Wayanad and Idukki Districts. Dates range from 10,000 BC to 6,000 BC. All of them are associated with burial system. ‘Nannangadi’ was the burial jar. Dolmens belonging to this period have been unearthed from Idukki district. Stone age carving in Edakkal Caves had pictorial writings believed to be dating to at least 6000 BC, from the Neolithic man, indicating the presence of a prehistoric civilization or settlement in this region.
From as early as 3000 BC, Kerala had established itself as a major spice trade center. Kerala had direct contact across the Arabian Sea with all the major Red Sea ports and the Mediterranean ports as well as extending to ports in the Far East.
The important palaeolithic sites are Valuvasseri (Nilambur) and Tenkara (Palaghat) and the mesolithic sites are Walayar (Palaghat), Mankara, Tenmalai (Kollam).
Links with Indus valley civilization 
From 3000 BC onwards Kerala had trade relations by sea with the Indus Valley people. The caves contain drawings that range over periods from as early as 5000 BC to 1000 BC. Recently the youngest group of paintings were in the news for a possible connection to the Indus Valley Civilization.
Historian M.R. Raghava Varier of the Kerala state archaeology department identified a sign “a man with jar cup” that is the most distinct motif of the Indus valley civilization. The finding made in 2009 September indicates that the Harappan civilization was active in the region. Interestingly, the “a man with jar cup” symbol from Edakkal seems to be more similar to the Indus motif than those already known from Tamil Nadu and Karnataka.
Mr. Varier said “The discovery of the symbols are akin to that of the Harappan civilisation having predominantly Dravidian culture and testimony to the fact that cultural diffusion could take place. It is wrong to presume that the Indus culture disappeared into thin air.” The scholar of Indus and the Tamil Brahmi scripts, Mr. Iravatham Mahadevan said the findings were very significant called it a "major discovery".
See also 
- History of Kerala Early History Civilization
- Protecting megaliths to keep history alive The Hindu daily
- Muniyaras are in a state of ruin The Hindu daily
- Where history lies buried The Hindu daily
- A wedge of the past The Hindu daily
- "Archaeologists rock solid behind Edakkal Cave". The Hindu (Chennai, India). 2007-10-28.
- The New Indian Express daily
- Symbols akin to Indus valley culture discovered Hindustan Times daily
- "Symbols akin to Indus valley culture discovered in Kerala". The Hindu (Chennai, India). 2009-09-29.