Beginning in the 1930s, the father of Dr. Javier Cabrera, Cultural Anthropologist for Ica, Peru, discovered many hundreds of ceremonial burial stones in the tombs of the ancient Incas.
Dr. Cabrera, carrying on his father's work, has collected more than 1,100 of these andesite stones, which are estimated to be between 500 and 1,500 years old and have become known collectively as the Ica Stones.
The stones bear etchings, many of which are sexually graphic (which was common to the culture), some picture idols and others depict such practices as open-heart surgery and brain transplants. The most astonishing etchings, however, clearly represent dinosaurs - brontosaurs, triceratops, stegosaurus and pterosaurs.
While skeptics consider the Ica Stones a hoax, their authenticity has neither been proved or disproved.