Massive cascades of Petrohué Waterfalls pour through the lush, volcanic landscape, flowing across dramatic basalt formations, brought to the surface eons ago by snowcapped Osorno Volcano. Its naked peak rises photogenically above the falls, two fantastic natural attractions protected as part of Vicente Pérez Rosales National Park.
The chill river, which flows between Lago Todos de los Santos and and Lago Llanquihue, doesn't hold much appeal for bathers; most visitors are content to hike around the pastoral countryside. Keep an eye out for "torrent ducks" however, tiny but tough birds who can navigate the rapids with a dozen chicks in tow.
The Petrohué Waterfalls are located close to the Lago de los Todos Santos, on the eastern slopes of Osorno Volcano, just within the borders of Vicente Pérez Rosales National Park. The vast majority of visitors visit on a day trip, as all but the hardiest travelers will need private transportation and a guide.
However, if you're planning to make the incredibly scenic border crossing between Puerto Montt, Chile, and Bariloche, Argentina, you have another option. The bus-boat-bus trip is offered as a package from either city, and can include visits to several scenic, difficult-to-access spots (including the waterfalls) en route.