It is 16 km long and takes 2 to 3 days to complete. Park Rangers guide this trail which leads to Puyehue Volcano, the Sulphur deposits and the Thermal Baths. There is a rustic mountain hut on the foothills of the volcano which can accommodate up to 12 people.

The area is one of wet, evergreen forests which surround more than 20 lakes and crystalline lagoons with snowcapped slopes. Strong rivers descend from the peaks of the Andean massif, trees climbing as high as 45 m and whose dense foliage scarcely lets the sunlight through, are laden with ferns and moss. The land in this protected area is covered in forests of native trees like tepa, mañio, Guaiteca cypresses, luma, arrayán and olivillo, just to name a few. 

In the wooded areas there are not many mammals, although you will be able to see coypus, foxes and skunks. You should also be able to see otters that live in the rivers and lakes, and the vizcachas and mountain monkeys which inhabit the higher areas near the craters. The largest bird populations are torrent ducks, black woodpeckers black throated huet-huets, harriers, condors, slender billed parakeets, great grebes, wrens and black faced ibis.