The Marble Chapel is a national monument of Chile, consisting of a series of mineral formations made of calcium carbonate. It is located on the western shore of General Carrera Lake in the Aysén Region, near Puerto Río Tranquilo and 223 km south of the regional capital, Coyhaique.

Over the years, the waters of the lake—the second largest in South America—have eroded the coastal cliffs, creating these formations that include caves and islets. Some of these formations are also known as the Marble Cathedral, Marble Chapels, or Marble Caves. In recent years, they have become a major tourist attraction in the Aysén Region.

The term "Marble Chapel" is thought to have been coined at the end of the 19th century or early 20th century, alongside geographic research conducted to define the border between Chile and Argentina. One of the oldest records is found in the pages of a text called *Climbing the Andes*, written by the Italian-Argentine explorer Clemente Onelli and published in 1904.