The hills of Kalamata, on the southern coast of Greece's Peloponnese peninsula, produce some of the best olives in the world. When pressed, they produce an oil that is almost fluorescent green and sometimes described as "liquid gold."

EPA/ALI ALI
But after much of that oil is pressed in Greek processing facilities, tanker trucks come to take it straight to the sea. In 2012, 60 percent of Greece's olive oil output was shipped to Italy. There, it is packaged in Italian bottles with Italian labels, and then sent around the world. And most of the profits go back to Italy -- according to consultancy McKinsey, Italy captures an extra 50 percent premium on the price of Greek oil.
