El Dorado -- its very name has become synonymous with legend of a mythical city of gold lost in the wilds of South America. But is it really a myth? Is there actually a city packed with gold hidden somewhere in the Andes? For hundreds of years explorers have mounted expeditions to find it. Now Olly has learned of new clues that could mean one of the greatest archaeological discoveries of all time is right around the corner. From the golden churches of the Incan capital Cusco, Olly follows the trail of El Dorado along a road of ruins deep into the remote Andes Mountains, leading an expedition that promises to open a new chapter in the centuries-old hunt for the City of Gold and change the face of archaeology.