One of the most remote corners of the country: more than 600,000 hectares of sand dunes and dry forest along the Bolivian border, above the Yrenda aquifer and including much of the Timané River. It borders Defensores del Chaco and Bolivia's Kaa-Iya park, forming a continuous belt of protected areas. It's a strict conservation area that can only be explored on organized expeditions, with well-equipped vehicles and coordination with the Ministry of the Environment, but it rewards you with the feeling of being in almost untouched land.

It was created on August 12, 2003 (Decree 21,957) and expanded in 2016 by Law 5723 to some 605,000 hectares. It protects Chaco War sites such as the Picada de la Desesperación (the “Trail of Despair”), where thousands of Bolivian soldiers died, with remains of trenches, vehicles and ammunition. It is the ancestral territory of the Guaraní Ñandeva and of Ayoreo living in voluntary isolation.