Petrohue sits at the western end of Lake Todos los Santos, a deep green lake in the shadow of Osorno volcano, and the small settlement is the end of the road for anyone driving up from Puerto Varas. Osorno, a near-perfect snow-capped cone of about 2,650 metres, dominates the horizon, and on a clear morning it is reflected in the lake's still water. La Ensenada, a hamlet on the shore of Lake Llanquihue, is the last real settlement before the final stretch.
The ride is a pleasure from start to finish. From Puerto Varas the road runs along the edge of Lake Llanquihue, with long, easy bends, views across the water to the volcano and the sweet smell of cut grass and pine. Past La Ensenada the road climbs into forest, passes lava fields and winds along the Petrohue River to the lake. The surface is good, the corners are gentle, and the main hazard is slow traffic of tour buses and cars at weekends. Early morning is best, and summer and early autumn bring the most reliable weather, though rain can arrive from the Pacific in any month.
The area has a layered past. The valley was settled by German immigrants in the nineteenth century, who cleared forest for farms around Lake Llanquihue, and the architecture of nearby towns still has a distinctly German flavour. The park around Petrohue, Vicente Perez Rosales, is the oldest national park in Chile, established in 1926. Todos los Santos was an old route across the Andes, used by Jesuit missionaries and later by travellers crossing to Argentina, and a boat and bus link across the lake still carries passengers to the border and on to Bariloche.
The nature is the draw. The Petrohue Falls, a short walk from the road, crash through channels of black volcanic rock into a turquoise pool, the rock itself left by ancient lava flows from Osorno. The forest is thick with southern beech, ferns and bamboo, and the volcanic soils are dark and rich. Condors circle overhead, and the cone of Osorno is usually wreathed in cloud before sunrise.
Fuel is available in Puerto Varas and along the lake shore, but not at Petrohue, so fill up before the climb. Bring a jacket, since the lake air is cool, and allow time for the falls.