Quebrada del Toro

The Quebrada del Toro is the great corridor between the humid Lerma valley around Salta and the high, dry puna, and both the RN51 and the old Salta to Antofagasta railway climb it side by side. Starting among sugar cane and green hills, the canyon narrows into red rock walls, then opens as the road gains height, the vegetation thinning from forest to cactus to bare scree while the river below shrinks to a braid of grey stones. Along the way are the ruins at Santa Rosa de Tastil, the village of Campo Quijano at the entrance, and the extraordinary railway engineering of spirals and zigzags built to gain altitude, visible from the road in several places. It is the route the Train to the Clouds follows, and it can be driven independently.

What you actually see

• The red rock narrows - the tight, colourful section in the lower canyon.
• The railway works - spirals, bridges and zigzags carved into the mountainside.
• The change in vegetation - forest giving way to cactus and then bare puna.
• Santa Rosa de Tastil - the pre-Inca ruins on a hillside along the route.

When to go

April to November, when the river crossings are low and the gravel sections firm; summer storms send flash floods down the canyon and can close the road. Morning light works best driving west. The full climb to San Antonio takes about three hours with stops.

Honest expectations

Sections are unpaved and rough, with fords that rise quickly in rain, and the altitude gain is steep enough to be felt. There are few services along the route. Driving it independently misses the railway experience, which is only available on the train.

Nearby

Campo Quijano guards the entrance; San Antonio de los Cobres and the puna lie at the top.