Marble Caves, Lago General Carrera (Lago Buenos Aires), Patagonia, Chile, Argentina

The Buenos Aires or General Carrera is a lake located in Patagonia and shared by Argentina, where it is known as Lago Buenos Aires, and Chile, where it is called Lago General Carrera. Both names are internationally accepted.
The lake has a surface of 1,850 km² of which 970 km² are in the Chilean Aisén Region, and 880 km² to the Argentine Santa Cruz Province, which makes it the biggest lake in Chile, and the fourth largest in Argentina. In its Western basin, Lake Gen. Carrera has 586 m maximum depth (Murdie et al. 1999, Geo-Marine Letters 18:315-320).
The lake is of glacial origin and is surrounded by the Andes mountain range. The lake drains to the Pacific Ocean on the west through the Baker River.