Cerro Guanaco is a mountain in the Fuegian Andes in southern Tierra del Fuego. It sits on the end of a ridge that runs from Chile, across the international border into Argentina, and lies within the Lapataia Sector of the Tierra del Fuego National Park. The NP is readily accessible from Ushuaia, the principal city and hub in the immediate region. The Fuegian Andes lie to the east of Cordillera Darwin and mark the southerly extent of the whole Andean range.