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Deep in rural Chilean Patagonia, melting glaciers feed South America’s 2nd largest lake, General Carrera Lake. Covering an area of almost 1000 square kilometres, it spans the border between Chile and Argentina.
Hidden along the lake’s western shore, inaccessible from land, stands the spectacular natural wonder of the Marble Caves.
The Marble Caves
As the summer sun breaks over the lake’s calm turquoise waters, we climb onboard a small boat, clad in wooly hats, gloves, winter coats and brightly coloured life jackets.
Early summer this deep into Patagonia remains chilly. Warned the wind on the lake can pick up to quite a bluster, we dressed for the cold.
Another 5 passengers joined us for a boat ride on Christmas morning to visit one the highlights of our Carretera Austral road trip.
How are the caves formed?
For over 6000 years, the Patagonian wind and waves have shaped and smoothed the calcium carbonate rock. When the water levels were higher than they are today, the calcium carbonate dissolved faster at the surface of the lake, so creating the cave system.
The caverns and tunnels of the Marble Caves
The Marble Caves are actually made up of 3 main features: the cave (Cuevas de Mármol), the chapel (La Capilla de Mármol) and the cathedral (El Catedral de Mármol).
When is the best time to visit?
You can visit the Marble Caves year round although the boat operators won’t take their boats out when the lake is too rough.
The best time of year to visit in during the summer months, from December to late February because the Carretera Austral is most accessible then.
Water levels on the lake are at their highest late summer so try to visit earlier in the season. Low water levels expose more of the shaped marble and boat trips can get further into the tunnels.
Visit early in the morning for the best colours. A combination of the low sun, and refraction of light from the turquoise lake surface shrouds the Marble Caves in bright blues, greens and yellows.
Check out our definitive guide to the regional seasons to find the best time to visit Patagonia.
Where are the Marble Caves?
The Marble Caves are on the western coast of General Carrera Lake near the town of Puerto Rio Tranquilo.
Along the Carretera Austral, Puerto Rio Tranquilo is 215 kilometres south of Coyhaique, 70 kilometres north of Cochrane and 165 kilometres west of Chile Chico on the border with Argentina.
How do I get to there?
The best way to get to the Marble Caves is as part of a Carretera Austral road trip. This way you can take your time, hang out in the laid back town of Puerto Rio Tranquilo waiting for the best conditions before you take the boat trip.
Once in Puerto Rio Tranquilo, you’ll see a dozen or so wooden huts on the coast housing all the tour agencies.
Speak to a few of them to compare their tours and prices and don’t be afraid to negotiate. If you can get a group together, you’re more likely to get the price down a bit more.
Expect to pay around 10000 CLP / $15 US for 2 hours.
You can also arrange kayaking tours for about 30000 CLP / $45 US for 3 hours. You’ll launch from Puerto Marmol, about 500 metres from the Marble Caves.
Where to stay in Puerto Rio Tranquilo
If travelling in a self contained campervan, use iOverlander to find an ideal free camping spot nearby.
If travelling in a car, check out these car camping essentials so you can take advantage of the multiple wild camping locations throughout Patagonia.
We stayed on the X-728 road towards Exploradores Glacier (our favourite road on the Carretera Austral).
The town has a few hostels and hotels you can book in advance. You can browse for availability here.
Tips for visiting the Marble Caves
- Wrap up warm and expect to get wet. The water can get pretty rough on the lake making for an uncomfortable journey and you could get a soaking. The Marble Caves get a little shelter so things calm down once you reach the main attraction.
- Pack your camera gear in a dry bag.
- There’s no ATM in Puerto Rio Tranquilo and few places accept card payments.
- Bring enough cash for your stay.
- Find our the best time to go to Patagonia for the things you enjoy.
- Book a cheap flight to Patagonia with Skyscanner. Better still, if you’re planning a long term trip, ship your camper van to South America like we did!
- Plan a rough itinerary with an idea of how long you’ll stay in each place. But be flexible - Patagonia will get under your skin and you’ll wish you had more time. Get a copy of the Moon Patagonia travel guide to help you plan your itinerary.
- If you want to explore Patagonia in a rental car, make sure to book in advance. Especially if you travel between December and February. Get free comparison quotes with rentalcars.com.
- Check out our extensive and still growing guides to Patagonia for more information on both Chilean and Argentinian Patagonia with places to go, things to do and see & loads more.
- Book your accommodation in advance, at least for the first destination. For hotels, use booking.com. For apartments use Airbnb and get a discount on your first booking. For free camping, use the iOverlander app offline.
- Try to learn Spanish or at the very least have some basic phrases. English is widely spoken in the major tourist towns in the south, like El Calafate, El Chalten and Puerto Natales. Everywhere else, you’ll need some basic language skills to get the most out of your trip.
- Reserve your tours and activities in advance with Viator and Get Your Guide.
- Get your rucksack ready with our definitive Patagonia packing list.
- Go have the adventure of a lifetime!
We hope this helps you plan your travels in Patagonia. It’s an enormous region and one we completely adore. Yet we found it difficult to planning our first trip, so we've written so extensively about it to help you out!