This is the biggest part of the Park, covering an extension of 1'800, 000 hectares of pristine forest.

A few protected areas in the world are as large as this Intangible Zone and non of them is as pristine as rich in wildlife species.

In this area, tourism is not permitted and for that matter any other activity, except Scientific researchers at the Biological Station of Cocha Cashu where for the last 25 years peruvian and international scientists have been conducting investigation projects on flora and fauna.

There are several ethnic groups such as Matshiguenkas/Kugapacoris, Yoras/Yaminahuas, Mashco Piros, Amahuacas and others, some of this groups don't have any contact with the outside world.