Located on General Carrera Lake, also known as Buenos Aires Lake depending on which side of the lake you are, the marble caves are an unusual geological formation with Marble Chapel and Marble Cathedral located at the centre of the lake and representing a group of caverns, columns and tunnels formed in monoliths of marble. The caves are on the Chilean side of the lake and have been formed by a wave action over more than 6,200 years ago.
The amazing vibrant blue and grey cave chambers lay in the mesmerizing turquoise waters of the lake and you can travel in a small boat or kayak, only when the weather is nice and the water is mostly still. The lake is of glacial origin and is surrounded by the Andes mountain range, draining to the Pacific Ocean on the west through the Baker River. Even though the weather in the area is generally cold and humid, the lake itself has a sunny microclimate. While the Argentinean side of the lake is quite easy to reach, the Chilean side has been mostly isolated and was for years accessed through Argentina, until the building of Carretera Austral which now connects the lake to the rest of Chile, thus permitting the expansion of tourism in the area. Nowadays a ferry operates between Puerto Ingeniero Ibanez and Chie Chico in the Chilean sector of the lake.
Near the small town of Puerto Tanquilo cliffs of pure marble, the monoliths are rising from the lake water exposing the block of marble which weighs 5 billion tons. The stone is in dark grey color with frequent dark striations. The caves are not internationally known by many tourists but those who happen to discover the place leave mesmerized. Some of the boats organizing trips to the site even go underground through the marble tunnels but only when the weather is good.