Río Abiseo National Park

Río Abiseo National Park is located in the San Martín department of Peru. Situated on the eastern slope of the tropical Peruvian Andes in north-central Peru. A World Heritage Site, it is one of the few World Heritage properties inscribed for both cultural and natural values.

Río Abiseo National Park is home to many species of flora and fauna. It is also the location of over 30 pre-Columbian archaeological sites. Since 1986, the park has not been open to tourism due to the fragile nature of both the natural and archaeological environment.

Lying wholly within the Gran Pajatén Biosphere Reserve, its 274,520 ha (67,756 acres) not only harbors several forest types and high Andean grasslands known as Paramo but also extraordinary archaeological values spanning at least eight millennia of human history.

Río Abiseo National Park protects three distinct ecoregions: Ucayali moist forests at lower elevations, Peruvian Yungas at middle elevations and Cordillera Central páramo at the highest elevations

Scientists consider the forest part of the Pleistocene refuge, meaning that flora and fauna are believed to have survived and evolved here during periods of past glaciation. This is a plausible explanation for the astonishing diversity of flora and fauna and the high degree of endemism found in the forests and grasslands.

The numerous archaeological sites blend in harmoniously with the forests, canyons, and highlands – against the stunning backdrop of an unspoiled and remote part of the Andes

The number and variety of archaeological sites found to indicate a significant level of human occupation, which dates back to the preceramic era around 6,000 years B.C. and continued steadily until before European colonization.

The known ruins and other archaeological remains extend over more than 150,000 ha (370,000 acres) in and around the property. Since 1985, 36 archaeological sites have been recorded, 29 in the high elevation grasslands and seven within the continuous montane forests inside the park.

Types of features include rock shelters, roads, domestic and ceremonial structures, storage buildings, fences, platforms, agricultural terraces and burial sites. Trade relationships existed with places as far away as the Pacific Coast and what are today the Ecuadorian Andes.

Among these archaeological sites, Los Pinchudos and Gran Pajatén are worth highlighting:

• Los Pinchudos is an elaborate Chachapoya tomb complex, perched on a high rock cleft in one of Peru's northern Andean cloud forests. Los Pinchudos is located in Río Abiseo National Park, a natural and cultural World Heritage Site, guarded and closed to all except scientific missions.

  The clay and stone tombs of the complex have wooden roofs and are painted in red, yellow, black, and white colors. Anthropomorphic carvings featuring large phalluses are responsible for giving the site its name. Los Pinchudos is located very near the related site of Gran Pajaten.

• Gran Pajatén sits on a hilltop above the Montecristo River valley and consists of a series of at least 26 circular stone structures atop numerous terraces and stairways. The ruins occupy an area of about 20,000 sq m (215,000 sq ft). The principal buildings are decorated with slate mosaics displaying human, bird and geometric motifs.

  Analysis of ceramic samples and radiocarbon dates show that the area was occupied as early as 200 BCE, but the visible building ruins on the present site were constructed during Inca times. Based primarily on architectural evidence, the settlement is attributed to the Chachapoyas culture.

Río Abiseo National Park protects the headwaters of three major rivers of the Huallaga River system, a major Peruvian tributary to the Amazon. Both the Andean grasslands and the lowland, montane and cloud forests harbor impressive numbers of rare species, many of which are restricted to the property in their range.

Among the particularly noteworthy species is the critically endangered Yellow-tailed Woolly Monkey, one of the largest monkey species in South America, which was long believed to be extinct before its scientific rediscovery in what is today the property.

There are at least seven climate zones in the park, including montane forest, tropical alpine forest, montane rain forest, high Andean grasslands (puna), and dry forest. Rainfall ranges from 500 mm to 2000 mm (20 to 80 in) per annum.

The montane cloud forest, composing most of the Park area, is a high-altitude rain forest with short trees, moss and lichen. This ecosystem occurs above the altitude of about 2,300 m (7,550 ft). High humidity is constant and rain falls throughout the year, particularly at the higher elevations.