Cajon del Maipo

The Cajon del Maipo is the valley of the upper Maipo river running south-east from Santiago into the Andes, and it is the capital's weekend outlet: an hour from the city to hot springs, rafting, climbing, hiking and a chain of villages selling empanadas to people escaping the smog. Higher up are the Embalse El Yeso reservoir, the El Morado monument and the Valle de Colina springs. It has also been the focus of a long fight over the Alto Maipo hydroelectric scheme, which diverts water through tunnels under the range - opposed for years by residents and environmental groups on the grounds of what it does to the river and to Santiago's water.

What you actually see

• Santiago's weekend valley - an hour from the city into the Andes.
• Hot springs, rafting and climbing - what people come up for.
• El Yeso and El Morado above - the reservoir and the monument.
• A long hydroelectric fight - the Alto Maipo scheme and its opponents.

When to go

October to April; the upper valley is snowbound in winter. A full day.

Honest expectations

Weekend traffic on the single valley road is heavy and slow. The upper roads are gravel and need care. Winter closures affect the best parts. Public transport thins out beyond San Jose de Maipo.

Nearby

El Yeso reservoir is at the top; Santiago is down the valley.