We go on, leaving los Andes with The Atuel ... the longest river in Mendoza.
It is born in los Andes range, at 3,250 m above mean sea level, from the glacial Atuel Lake.
As it approaches the city of San Rafael, Mendoza, from the southwest, the Atuel is turned
into a reservoir with an area of 96 km˛ by the El Nihuil Dam.
Immediately after El Nihuil, the river becomes entrenched along a canyon and forms rapids.
The canyon is about 60 km long, and during its course the river falls from 1,250 to 700 m above sea level.

these natural colourful walls of stones form a part of this canyon..