Edekkal is point of attraction for many historians and archeologists. One can see huge numbers of cave arts (not painting rather engraved on stone) which dates back to the stone age. Humans had inhibited this place at different period of history. And there are some inscriptions which resembles to very old form ( 2000+ years) of Tamil language.
There are hundreds of arts engraved on the stone walls but the most astonishing ones are some motifs that are signature of Indus Valley civilization ! Can you believe? All the known sites of Indus Valley civilizations are thousands of miles far! So some group travelled all the way from western part of the country through dense forest and inhospitable terrains and reached a cave, on top of a hill at down south ? Or there must be some kind of contact between two civilizations! Interesting!