Natural Sanctuary Marble Chapels
Updated March 2025
I’m updating the info on this excursion because last season, the agency I currently work for, Zoyen, only offered it over two days and one night. This season, we’ve rolled out a new, shorter, more relaxing, and way more enjoyable format.
But let’s start from the beginning…
Location
To set the scene in space and time, this Natural Sanctuary is located in the northwest section of Lake Buenos Aires (General Carrera, Chile), in the XI Region of Aysén, Southern Patagonia, Chile. It’s a binational lake, the second largest in South America and the largest in Patagonia (considering Patagonia as one unified region of Argentina and Chile).
This lake is of glacial origin, like most of the ones near the mountain range. Where I live (well, lived—I just left a few days ago!), in the northwest region of Santa Cruz, we can find traces of the great glacier in every corner, its advance and retreat. In this case, its marks stretch a few kilometers east of the town of Perito Moreno, for example, and we see them as grooves called «Moraines» along the famous and mythical Route 40.
Mount San Valentín (the highest in Southern Patagonia) still holds the ancient glacial front that, in its retreat, created what we now know as Lake Buenos Aires. The area it’s located in is at the head of the Northern Ice Field, and from there comes the following hypothesis about the region’s name, Aysén: it comes from the English phonetics of «Ice – End,» because, according to the person who proposed the name, it marked the end of the ice field.
Back to Lake Buenos Aires, it actually appeared (apparently) on maps as early as 1746 with the legend «Chelen» (I think referring to Chelenko).
Hypotheses about its toponymy are abundant in various explorer accounts. Then, in 1881, Carlos María Moyano, who traveled through our region, named the lake Buenos Aires. In 1959, Chile decided to name its part «General Carrera.» The most accurate information about the original toponymy comes from the work of Marcelo Gavirati and Tegai Roberts, both from Puerto Madryn, who gathered the diaries of a Welsh explorer who was in the region, guided by the «baqueano» of the time: the Ahonikenk. A whole topic in itself that could be explored in much greater depth.
What are the Marble chapels?
These curious marble geoforms are a type of metamorphic rock. This means that one rock was transformed into another through metamorphism. In this case, the parent rock is limestone, which was subjected to pressure and high temperatures in a tropical climate millions of years ago. We can see the arch-shaped folds in the figure of the Cathedral, for example, which demonstrate this consequence. Later, through the action of water and other chemical reactions, the cavities or caves we see were formed.
The new Road
The general and conventional option to visit the Marble Chapels and Cathedrals is by reaching the town of Puerto Tranquilo, Aysén Region (Chile), located on the northern arm of General Carrera Lake. As I mentioned, for the past two seasons, the owners of the two receptive agencies in the region took the initiative to find a new dock, making travel times shorter, more relaxed, and more enjoyable. This option is now available ONLY FOR THOSE WHO BOOK THE EXCURSION, in this case, with Zoyen.
If you prefer to go on your own, you’ll need to get to Puerto Río Tranquilo, whether from Argentina or Chile. From Argentina, leaving Los Antiguos (a border town), you’ll be there in about 4 hours, as it’s 190 km of gravel roads with winding curves, steep climbs, and descents. It’s really not a route for just anyone…
On the Zoyen excursion, the trip is half that—just 90 km, about two hours of travel, with the transfer, lunch (Patagonian lamb, depending on conditions), amenities, and navigation included. A real treat!
To sum it up: If you go on your own, you’ll need to drive to Puerto Río Tranquilo. If you book the excursion, the trip from Argentina is half the time, as the dock is in the small town of Mallín Grande.
As a fun fact, the Chapels can’t be seen from the road, and the boat used is an open vessel with seats for up to 35 people. There are no catamaran-type boats on the lake.
A bit of history
This Natural Sanctuary was brought to light not long ago. The area was explored as part of the Boundary Commissions, and one of the first explorers to mention the Chapels was Clemente Onelli in his book Trepando los Andes at the end of the 19th century.
Later, Arnold Heim, a Swiss geologist who studied the General Carrera Lake region a little later, in 1939, was the one who coined the name by which they are known today and provided the geological data I mentioned earlier.
The place began to gain recognition due to the large number of fishermen who arrived in the area to fish. The first agency was Queulat, from the Coyhaique region, which specifically brought fishermen, and they themselves would share stories of the potential beauty of the area. It wasn’t until 1990, when the southern section of the Carretera Austral (Route N7) was completed, that it became accessible to reach the area. The region’s main issue had always been the lack of connectivity and roads that linked the destinations. It was then that tourists from all over the world started to arrive, and today, it has become a highly visited and globally recognized site.
Photographs of Arnold Heim published by Wolfgang Staub in his book «Arnold Heim: un geólogo suizo en la cuenca del lago Buenos Aires/General Carrera» (2009).
I hope all this information has been useful to you! If you think anything is missing or if you have any questions or suggestions, don’t hesitate to let me know!
As I always say, I’m not a historian, geologist, or anything related to the world of sciences, but I do consider myself a great reader and curious enough to create this kind of content.
