In Venezuela, one of the world's largest deltas forms a gateway to Latin America. After Christopher Columbus, the Orinoco was the course followed by the conquistadors who pushed ever further upriver in their search for the mythical Eldorado. Today, the descendants of the survivors of the Spanish invasion live on the banks of the river. Travelling up the Orinoco is like travelling through time, unearthing the secret roots of Latin America, from its founding myths in Ciudad Bolivar to the vestiges of its lost civilizations.