Romanée-Conti is one very expensive example of why European wine is so appealing to collectors around the world. History, reputation and the incredible beauty of vineyard landscapes draw oenophiles to dozens of renowned regions, from Barolo to Pantelleria, Burgundy to Bordeaux, Priorat to Jerez, and Germany’s Mosel to Portugal’s Douro Valley. Italy alone is home to more than 350 official grape varieties, though altogether the country grows more than 1,300, some so local they exist only in a single tiny valley.