On a sun-washed July afternoon, Brian Bauer, an archaeologist from the University of Illinois at Chicago, stands in the plaza of the sprawling Inca ceremonial site of Maukallacta, south of Cusco.

So our little gold llama is a rare survivor. Gold was the emblem of the great Inca sun-god, and represented his generative powers. Gold was described as "sweat of the sun" just as silver was the ...