(WSJ) - SUCH HAS BEEN the success of South America's wine-producing duopoly of Argentina and Chile, which has stormed the international market with interpretations of Malbec and Carménère, that it is easy to overlook the continent's other wine industries. Brazil makes attractive red wines and good-quality sparkling wine, while Peru has also seen its wine production increase, notably in the Ica Valley. But outside of Chile and Argentina, it is along the South Atlantic coast where the vine really thrives. Welcome to Uruguay, one of the most intriguing wine-producing countries on the map.

Its vineyards, which cover an area of around 9,000 hectares, are in a cluster of regions that fan out from the capital, Montevideo, and include Maldonado, Canelones, San José and Colonia. Here the Atlantic's influence is key. Like Bordeaux on the other side of that great ocean, the hot summer weather is tempered by the sea breeze, which slows the ripening process and gives the wines a unique (and welcome) aromatic profile, a pleasing freshness and bright acidity.

Tannat, the small, dark-berried grape variety made famous by the Madiran appellation in the southwest of France, is the primary performer—mainly because it can handle the rain and doesn't tend to succumb to rot. It was first imported in the late-19th century by migrants from Spain's Basque region. Unlike its counterpart in France, which can taste a little astringent when young, it is more supple and drinkable in Uruguay. Today, it is joined by other European grape varieties—including Merlot, Cabernet Sauvignon, Cabernet Franc and Viognier, Sauvignon Blanc and Chardonnay.