San Guillermo National Park

San Guillermo protects a stretch of puna and high Andean desert in the far north of San Juan, between roughly 1,800 and 6,000 metres, and it exists above all for its wildlife. The plains here hold the densest populations of vicuña and guanaco in the country, moving in herds across pale grassland, and they support in turn one of the strongest puma populations in Argentina, along with Andean condors, foxes and rheas. Beyond the animals the landscape is stark and enormous: volcanic cones, dry riverbeds, salt flats and wind-carved rock, with almost no vegetation above knee height. Access is strictly controlled, requires permits and a capable vehicle, and the park has no facilities at all, which is why very few visitors ever see it.

What you actually see

• The vicuña and guanaco herds - the largest concentrations in the country.
• The puma country - one of Argentina's strongest populations, rarely seen.
• The volcanic plains - cones, dry beds and salt flats across the puna.
• The condors - riding thermals along the ridges.

When to go

November to March, when the high routes are open; snow closes access for much of the winter. Weather is severe year-round with fierce wind. Trips must be planned around permits, which take time to arrange.

Honest expectations

There are no services, no marked trails and no rescue nearby, so this is expedition travel with permits, guides and self-sufficiency. Pumas are almost never seen even where they are common. The drive in is long and rough, and a single vehicle trip is unwise.

Nearby

Rodeo and the Iglesia valley lie south; the province of La Rioja borders to the east.