Patagonia's Marbled Caverns

Frequently, on this blog, I have described the Carretera Austral as Patagonia’s top road trip. I’m fortunate enough to revisit the area almost every year, but I haven’t yet described many of its attractions – which, despite the wild country, are often close to the highway.

At the town of Puerto Río Tranquilo, about 220 km south of the Aisén regional capital of Coyhaique via a mostly paved route, a cluster of roadside trailers, tents and containers advertise tours to the Capilla de Mármol, a string of swirling marble grottos at the west end of Lago General Carrera. It’s a huge lake, covering nearly 2,000 square kilometers in Chile and Argentina (where it goes by the name Lago Buenos Aires), but motorboat excursions to the caverns take only a couple hours – wind permitting. Trips are usually on a first-come, first-served basis.

Boatmen from Río Tranquilo carry half a dozen passengers or so to the grottos, gradually exposed to view by wave action over several thousand years. Marble is physically strong but chemically weak, accounting for the smooth surfaces.

Some of the grottos are small islands, but most of them hug the shore where, in good weather, the boats can enter. In some cases, passengers can leave the boat to explore the caverns, but walking even short distances on slippery marble entails a risk. The excursion is best in late summer or early autumn, when lake levels are at their lowest and boats can approach more closely and enter more deeply.

Puerto Río Tranquilo’s just a village with only about 500 residents but, returnin from the boat ride, there’s a new brewpub restaurant, Cervecería Río Tranquilo, just across the two-lane road. There’s also an improving accommodations scene, led by Refugio El Puesto.