The Marble Cathedral (Catedral de Mármol) (located next to the Marble Chapel) is a formation mineral of calcium carbonate, on the shores of Lake General Carrera in Chile. In 1994 it was named a national monument. Over the years, the waters of the lake have eroded the scarps coastal creating these formations, which when the lake is at a low level, you can go inside in small boats.
It consists of a few islets located a few meters from the lakeshore, which are named Cathedral Marble, Marble Chapel and Caverna Marble.
You can access these formations through the lake in small boats from the town of Puerto Río Tranquilo (in the municipality of Rio Ibanez, 223 km from Coyhaique, capital of the Aysen region ). From here you can rent small boats, which run through the area of Marble Cathedral.