Ñustapakana

The site is centered around a platform-like structure that contains an enclosure. Due to the absence of archaeological excavations, the function of this enclosure remains undetermined.^[2]

The enclosure is rectangular and is situated within the platform, adjacent to a retaining wall. On the interior, eight small niches are present on each of its walls. The entrance faces south, leading toward a wide platform that is bordered by a rock formation.^[2]

The platform is defined by two Inca-built stone retaining walls, constructed with a rusticated polygonal masonry pattern. An upper wall partially outlines the platform's shape, and a stairway is located on its northern side.^[2]

A pre-Hispanic road passes through the area. To the south, a wide canal is visible near a rock face and is defined by a side wall; this canal connects to other Inca-period sites scattered throughout the region. To the northeast, on the left bank of the river, there is a wall that was part of the river channel, built with polygonal cushion-type masonry.^[2]

The site is in fair to poor condition. The primary threat is erosion at the bases of the slopes, which has resulted in structural instability and causes movement of the stone elements at the top of the structures.^[2]

Cieza de León (1553), Toledo (1571), and Sarmiento de Gamboa (1572) attribute the construction of Saqsaywaman and its production and hydraulic systems to Yupanqui, Tupac Inca, and Guascar, who made rational use of its natural resources, employed advanced engineering technology, and also managed its organization and operation "...Inca Yupanqui ordered that twenty thousand men from the designated provinces come, and that the men and towns send the necessary provisions, although these Indians did not reside at the work site, but only for a limited time... one thousand of these broke the stones, the other seven thousand were brought along with large ropes made of cabuya leather, some going to the posts and beams for timbering, and overseers went about... his son Tupac Inca and Huascar did much work" (Cieza: 1553, Chapter II).^[3]

Ñustapaqana is situated in the Chacan sector of the Saphy micro-basin, northwest of the main esplanade of Saqsaywaman. The site lies at an altitude ranging from approximately 3,585 to 3,670 meters above sea level.

The topography of the area is characterized by steep slopes and a micro-basin configuration. The climate varies from warm and dry in the lower elevations to colder conditions at higher altitudes, with temperatures ranging between 6 °C and 12 °C. The sector experiences significant rainfall during the early months of the year, which supports dense vegetation, including native species such as queuna (Polylepis incana), chachacomo (Escallonia resinosa), and introduced eucalyptus forests.^[4]

• North: Senqa hill and lands of the Salkantay Community
• South: Chacan archaeological sector
• East: Lands of the Fortaleza peasant group
• West: Pucara sector

The Ñustapaqana sector is divided into two sub-sectors, designated A and B, based on architectural typology and spatial organization.

Located in the upper part of the sector, Sub-sector A consists of a single enclosure with an access opening oriented to the southwest. The interior features seven niches or alcoves. The structure is surrounded by a perimeter wall and includes a differentiated floor level. Larger, more dispersed structures are also present in this area. The state of conservation is poor, although walls are comparatively taller than those in Sub-sector B.

Situated in the lower part of the sector, Sub-sector B comprises a succession of terraces and open spaces. The structures are designed to control the slope topography, with retaining walls forming platforms. An enclosure associated with a carved rock outcrop is present, and the area has yielded a greater quantity of cultural material. Wall heights range from 0.30 to 1.50 meters, and the state of conservation ranges from poor to very poor, with some structures collapsed due to soil pressure and tree root activity.^[4]

The architecture at Ñustapaqana follows Inca canons, characterized by:

1. Rectangular and quadrangular enclosures with trapezoidal openings.
2. Single-story structures with slightly inclined walls.
3. Wall thickness averaging 0.70 meters
4. Use of local limestone with earth and clay mortar
5. Construction techniques ranging from rustic polygonal to fine masonry
6. Retaining walls and platforms adapted to the natural slope

One of the most significant components of Ñustapaqana is its hydraulic system, which forms part of the larger Chakan irrigation system. The site contains a canal running parallel to a retaining wall, designed to protect the water channel from erosion caused by soil creep and landslides. Historical sources attribute the initial layout of the Chakan irrigation infrastructure to Inca rulers such as Apo Manco Ccapac and Pachacuti Yupanqui.

The canal system was part of a broader network that supplied water to agricultural terraces in the Cusco Valley. Colonial documents from the 16th to 18th centuries describe the administration, maintenance, and water distribution systems associated with Chakan, including the role of water judges and the allocation of irrigation turns.^[4]

The Ñustapaqana sector is situated within the Yuncaypata Formation, composed of red siltstones, fine sandstones, and shales of Cretaceous age. Karst limestone outcrops are present in the area, belonging to the Yuncaypata Group. Quaternary deposits include colluvial and alluvial materials transported by gravity and water.

Geomorphological features include:

• Steep slopes (50–75% inclination) on limestone outcrops
• Moderate to gentle slopes in lower areas
• River terraces and alluvial plains

The site faces significant geodynamic risks, including:

1. Landslides: Active and ancient landslides have destroyed segments of Inca canals. A large landslide approximately 50 meters in height is present in the Saphy micro-basin.
2. Surface erosion: Caused by rainwater runoff on steep slopes with limited vegetation.
3. Karstification: Erosion of limestone outcrops through water infiltration

.

These natural processes, combined with human activities such as looting, inappropriate agricultural practices, and lack of maintenance, pose ongoing threats to the archaeological remains.^[5]

The state of conservation at Ñustapaqana ranges from poor to very poor. Key conservation issues include:

• Collapse and buckling of walls due to soil pressure and tree roots.
• Destruction of canal segments from landslides.
• Encroachment of rural expansion into the archaeological park.
• Absence of ongoing maintenance and management.

The Ñustapaqana Archaeological Research Project was conducted as a salvage operation to document and recover evidence before further destruction occurred. The project falls within the Archaeological Heritage Program of the Saqsaywaman Master Plan and complies with Peruvian cultural heritage laws (Law No. 28296, General Law of the Cultural Heritage of the Nation).