Spain is the world's largest producer of virgin olive oil, and 20% of the world's entire supply is produced in Jaén, Andalucia. Visit the Vía Verde del Aceite (Olive Oil Greenway) in the Sierra Mágina Mountains, where nine metal viaducts, designed by Gustave Eiffel, dozens of UNESCO World Heritage designated villages, and 34 miles of hiking and biking trails on a former railroad beckon. Essentially like visiting vineyards, a trip to the trail means getting to know olive growing culture: check out lush olive groves, visit farmhouses, see how olive oil is made, visit almazaras (mills where olives are crushed), and sample different variations alongside local cuisine.