Los Gigantes, Argentina, Granite mountain peak in San Alberto Department, Argentina.

Los Gigantes is a granite massif at the northern end of the Pampa de Achala, in the Sierras Grandes of Córdoba province. Its bare rock walls rise abruptly from the surface, eroded into named formations such as El Pollito, El Hornito, El Gorila and El Indio, with narrow galleries and small enclosed valleys between them.

Los Gigantes is a Precambrian granite massif whose exposed structural faults are visible in its rock walls. In 2001 the provincial government declared the area a Natural Protected Area because it is a source of water. Mining left its mark: mica is still extracted commercially, and a uranium plant that produced about 200 tonnes over eight years was shut down in 1990, leaving roughly 4,000,000 tonnes of material at the open site.

The name Los Gigantes, "the Giants", refers to the rock walls that rise abruptly from the surface. Erosion has shaped them into figures locals name El Pollito, El Hornito, El Gorila and El Indio, and the narrow galleries between them shelter plants adapted to altitude and sharp temperature swings. Guided visits reach caves such as La Cueva del Hornito and La Cueva de la Salamanca.

Access is via provincial route 28, about 28 km west of Tanti and roughly 80 km from Córdoba city. The massif is a water source within a protected area declared in 2001, so stay on trails and leave the rock walls and caves as found. Some caves, such as the Cueva del Hornito and Cueva de la Salamanca, can be entered only with a guide trained in speleology. Rock climbing and hiking are the main activities.

The caves here stay cool enough for ferns, tabaquillo, rosemary and peppermint to grow inside, and they shelter hikers too. Some, like the Cueva del Hornito and the Cueva de la Salamanca, can be entered with a guide trained in caving.