The site comprises more than sixty multi-ton T-shaped limestone pillars, most of them engraved with bas-reliefs of dangerous animals: not the docile, edible bison and deer featured in Paleolithic cave paintings but ominous configurations of lions, foxes, boars, vultures, scorpions, spiders, and snakes.
As if the challenge of pulling a 320-ton boat wasn't enough to deal with, the production was plagued by heavy rains, casting problems -- lead actor Jason Robards had to be replaced by Klaus Kinski due to illness, while Mick Jagger dropped out due to a Rolling Stones concert -- and a border war that broke out between Peru and Ecuador.