A private reserve on the Andean piedmont

Identity

El Ajial National Reserve is a Private Protected Area within Chile's National System of Protected Areas (SNAP), in the National Reserve category of article 56 of Law No. 21,600. Located in the Paine municipality, Maipo province, Metropolitan Region, it encompasses 2,134 hectares of Andean piedmont between 700 and 2,373 metres above sea level.

It is a representative relict of central Chile's Mediterranean ecoregion, one of the planet's 36 biodiversity hotspots. It belongs to the Southern Boundary Priority Site (Angostura) and is a link in the biological corridor joining Río Clarillo National Reserve with the Altos de Cantillana in the Coastal Range, connectivity that matters for large mammals and for resilience to climate change.

Origin

This private protected area was born from the long-term vision of Andrés Pérez Cruz and his family. Owner of the property since 1993, he was captivated by its landscape, forests, mountains and stream, and from the beginning protected the environment with the conviction that a productive project could coexist with conservation.

In 2011, together with Andrés Pérez Peric (today the Foundation's Executive Director) and a consulting ecologist, a technical survey was carried out on foot across the whole estate, identifying species and ecosystem services. That fieldwork produced the technical report that led to its designation as a Nature Sanctuary in 2016.

Milestones

Territory

The reserve lies on the southern boundary of the Metropolitan Region, on the foothills of the Andes, within the Paine stream sub-basin, in the El Ajial or El Escorial ravine. Its Huelquén and Chada accesses sit at 700 m a.s.l.; the ridges exceed 2,000 m and reach 2,373 m in the eastern sector, at the foot of Cerro San Francisco. The topography is rugged: deeply incised ravines on steep slopes and a network of permanent and intermittent watercourses draining to the Paine stream.

Seven vegetation formations cover the area: the sclerophyllous forest matrix, sclerophyllous scrub, the high-Andean steppe and Andean scrub of the upper sector, the hygrophilous forest of the ravines, rock outcrops and the thorn forest of the valley. See the formations and their areas.

Cultural heritage

The reserve holds the Pucará El Peral, a pre-Hispanic archaeological site of Inca affiliation at 720 m a.s.l., recognized in the reclassification resolution and safeguarded by its own Historic-Cultural Use zone in the Management Plan. A double-faced perimeter wall crowns the El Peral hill. Rubén Stehberg's excavations interpret it as part of the system of Inca installations that sacralized and controlled the Angostura pass: more than a checkpoint, a ceremonial place from which the territory was read.

The site is catalogued by Código Andino, record ch0005 (opens in a new tab)↗, an organization devoted to the study and conservation of pre-Columbian archaeological sites of Andean America, which collaborates with the Reserve on the trail's interpretation. The Chada ruins lie in the immediate surroundings. Any intervention requires authorization from the National Monuments Council, whose jurisdiction over both sites remains.

Legal status

National Reserve recognized by Exempt Resolution No. 1,012 of the Ministry of the Environment, dated 27 February 2026, under Law No. 21,600. Successor to the Nature Sanctuary established by Supreme Decree No. 4 of 2016. Under the non-regression principle, its boundaries, area and conservation targets remain intact. The area is managed by the Fundación Santuario de la Naturaleza El Ajial under the supervision of the Biodiversity and Protected Areas Service.

This reclassification allows us to keep dreaming and acting for a healthier and more vibrant territory for future generations.Andrés Pérez Peric · Executive Director