(WSJ) - With thousand-dollar bottles, complex classifications and a dizzying number of estates, this great French wine region is difficult to comprehend. Here, a simplified guide to the territoire—plus some surprisingly affordable offerings. There are only a handful of wine regions that manage to transcend mere geography to achieve true iconography. One of the first—and arguably still the best—is Bordeaux. This roughly 300,000-acre region in southwest France has been a reference point for the world's winemakers for hundreds of years and a sought-after address for aristocrats, billionaires and the occasional oligarch, too. But Bordeaux is much more than a single region or type of wine; it's an increasingly fractured place where the big names (Lafite, Latour and Mouton) turn out wines that sell for thousands of dollars while the lesser crus and the unknowns (just about everyone else) are forced to scrabble after a euro or two.