 Truffles grow only in a few places in the world | We are in the Tuscan town of San Miniato for the "gold rush," when the Italian white truffle comes into season. Truffles grow underground, close to the roots of oak, hazel, poplar and beech trees. It's this rarity that makes it so prized. Truffles are one of the world's most expensive foods and the Italian white is the most valuable, with a market price of up to €4,000 ($4,400) per kilo. |  |
 | The San Miniato Hills, with their mild Tuscan climate and soil rich in mineral salts, are the perfect breeding ground for top-quality truffles -- as well as the wine and olive oil for which the region is world famous. There are 63 types of truffle found worldwide. But Tuscany's "King Truffle" is the most prized of them all. |  |
 | San Miniato is on the ancient Via Francigena pilgrim route that stretches from Canterbury, England, to Rome. Today's pilgrims come for the annual truffle festival held here during the last three weekends in November, when the normally sleepy town fills with life. White truffle season lasts from October to late December or early January. A truffle can be stored, wrapped in paper in the fridge, but only for up to 10 days. |  |
 It's a 25-gram golden-brown beauty, worth up to $100. | Salvatore Cucchiara kneels down to unearth a truffle, brushing at the soil with his fingers with the care of an archeologist.  |  |
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