20130129_Chile_0554 Lake General Carrera
Erosion of marble cliffs in an arm of Lake General Carrera (Lago General Carrera) has created unusual islands with interesting openings that are known as the Marble Caves
[48% of the lake is in Argentina where it is known as Lake Buenos Aires. The Marble Caves are in the Chile portion. The lake is the largest in Chile and the fourth largest in Argentina.].
On Google Earth:
Marble Caves 46°32'46.07"S, 72°42'8.09"W