To hear porteños (inhabitants of Buenos Aires) talk of their city, you'd think Argentina stops where Buenos Aires ends. Not far beyond it, however, the skies open up and the pampas—Argentina's huge flat grasslands—begin. Pampean traditions are alive and well in farming communities that still dot the plains that make up Buenos Aires Province.

The best known is San Antonio de Areco, a well-preserved provincial town that's making a name for itself as gaucho central. You can ride across the pampas and get a taste of country life (and lots of grass-fed beef) by visiting—or staying at—a traditional estancia (ranch).

Ranchland gives way to watery wonders. The quiet suburban town of Tigre is the gateway to the network of rivers and tributaries that form the delta of the Paraná River, lined with luscious tropical vegetation. Low wooden launches speed along its waterways to the houses, restaurants, and lodges built on stilts along the riverbanks.

If you like your natural wonders supersized, take a short flight or a long bus ride to Iguazú Falls, northeast of Buenos Aires in semitropical Misiones Province. Here, straddling the border between Argentina and Brazil, two natural parks contain and protect hundreds of roaring falls and a delicate jungle ecosystem. The spectacle caused Eleanor Roosevelt to exclaim "Poor Niagara!" but most people are simply left speechless by the sheer size and force of the Garganta del Diablo, the grandest falls of them all.