Mount Inca Viejo

Mount Inca Viejo is located in the Ratones basin, in the Puna of Salta, north-western Argentina, reaching a maximum height of 4420m above sea level (m asl) (Figure 2). It rises around 700m above the surface level of the Ratones salt flat. The archaeological record at Mount Inca Viejo largely reflects mining-ritual practices (López et al. Reference López, Coloca, Rosenbusch and Solá2018; Coloca & López Reference Coloca and López2021). Although the record spans pre-Inca and Inca periods (between c. AD 700 and 1500), the Empire’s appropriation and modification of the mountain highlights a period of economic and ceremonial significance during the latter half of the fifteenth century and the early sixteenth century (López et al. Reference López, Coloca, Orsi, Araya, Seguí, Rosenbusch and Solá2020). This importance stemmed from the mountain’s mining potential, especially as a source of turquoise and other copper minerals. Various indicators of pre-Hispanic mining are recognised, such as wells and galleries associated with built structures, lithic hammers and anvils (Figure 2; Coloca & López Reference Coloca and López2023). At the summit sits a quadrangular structure (6.2 × 6.2m) of carved rocks and double-row walls (Figure 2A); similar architecture is observed elsewhere on the mountain (Figure 2E & F). Additionally, Inca roads were recorded (Figure 2D), including a main one that ran from north to south on the eastern slope of the mountain.

Figure 2. Inca-era archaeological features on Mount Inca Viejo (figure by authors).

On the western slope, at 4312m asl, is Cueva Inca Viejo, a pre-Hispanic cave mine that has a main chamber (Figure 2C) and secondary galleries opened for the exploitation of minerals (López et al. Reference López, Coloca, Orsi, Araya, Seguí, Rosenbusch and Solá2020). Inside, an archaeological assemblage related to mining and ritual activities was recorded (see below), along with wall paintings including motifs of llama caravans, anthropomorphic figures and other figurative and geometric representations. On the slope at the entrance to the cave, an ushnu-type ceremonial structure with a platform and staircase was completely covered by sediments and rocks until its rediscovery in 2017 (Figure 2B; López et al. Reference López, Coloca, Orsi, Araya, Seguí, Rosenbusch and Solá2020). Within this structure, three monoliths were found, two whole and one fragmented, that are reminiscent of standing stones recorded in other Inca ceremonial contexts (Coloca & López Reference Coloca and López2021). The cave and its surroundings have previously been interpreted as a waka mine (e.g. López et al. Reference López, Coloca, Rosenbusch and Solá2018); here, this interpretation is explored further, concurrently with the assessment of Mount Inca Viejo as a sacred mountain, particularly during the Inca Period.

Further east on the mountain is the Abra de Minas site (4250m asl), a settlement with 92 structures. Inca architecture is observable in the compound perimeter enclosures (kanchas), a rectangular ‘great hall’ (Kallanca) and a quadrangular platform that would correspond to an ushnu (López et al. Reference López, Coloca, Orsi, Araya, Seguí, Rosenbusch and Solá2020; Coloca & López Reference Coloca and López2021). This settlement may have functioned as both an enclave to control the mining of Inca Viejo and as a residence for miners (López et al. Reference López, Coloca, Orsi, Araya, Seguí, Rosenbusch and Solá2020).

Sacred mountains in north-western Argentina

In pre-Hispanic times, particularly during the Inca period, many Andean mountains were held as sacred, which is why they were often referred to as high-altitude sanctuaries. Atop these mountains, shrines are characterised by the remnants of rituals or ceremonies, including the capacocha (Beorchia Nigris Reference Beorchia Nigris1985; Schobinger Reference Schobinger1999; Reinhard Reference Reinhard2006; Ceruti Reference Ceruti2007; Cruz et al. Reference Cruz, Crubézy and Gérard2013; Vitry 2023). Yet the sacredness of a mountain was not solely related to its height, other features, such as the presence of minerals of symbolic value, water flows, morphology and location, also played a part (Cruz Reference Cruz2009; Platt & Quisbert Reference Platt and Quisbert2010).

Although variability is recognised in the composition of sacred mountain sites, certain recurring features can be identified, such as ceremonial structures or platforms, monoliths, animal and plant remains (e.g. Spondylus sp. shells, bird feathers and firewood), minerals, anthropomorphic and zoomorphic figurines, and human or animal sacrifices (Beorchia Nigris Reference Beorchia Nigris1985; Reinhard & Ceruti Reference Reinhard and Ceruti2005; Vitry 2023). Such sites have also been interpreted as pilgrimage centres (e.g. Mignone Reference Mignone2017; Leibowicz et al. Reference Leibowicz, Moyano, Ferrari, Acuto and Jacob2018), yet whether they represent a destination for pilgrims or a stage for ceremonies, the activities performed at these mountain-top sites were related to the cult of the mountains.

The Inca domination of the mountains in the central-southern Andes involved a high level of organisation, reflected in the shared archaeological attributes of high-altitude sites. In addition to ritual indicators (platforms, monoliths, sacrifices, etc.), Inca domination can also be defined through the presence of kanchas—located at the foot or on the slopes of mountains—ceramics, stone working, textiles, metallurgy, mining and associated roads and accessory constructions, particularly on the summits (Raffino Reference Raffino1981).

In contrast to earlier periods, the Incas invested a considerable amount of labour in creating this high-altitude landscape, marking the materialisation of Inca control over the mountains (Vitry Reference Vitry, Terra and Andrade2008, 2023). It has been proposed that several Andean mountains were integrated into a spatial and religious formation delineated by ceques, imaginary lines that connected different sectors of the Empire, with the heart of Tawantinsuyu in Cusco, Peru, serving as the main reference point (Rowe Reference Rowe1981; Bauer Reference Bauer1998; Zuidema Reference Zuidema2010; McEwan Reference McEwan, Meddens, Willis, McEwan and Branch2014; D’Altroy Reference D’Altroy2015). Within this framework, a recurrence of sacred mountains has been observed, with high-altitude archaeological traces predominantly found in the southern regions of the Empire, particularly in what was known as Collasuyu. Most of the more than 200 currently identified Inca mountain sites (96%) are in north-western Argentina, northern Chile and southern Peru (Vitry 2023).

In the Argentine Northwest, where this research is focused, certain attributes of sacred mountains vary, including the presence or absence of human burials, which are generally associated with the capacocha ritual (Reinhard & Ceruti Reference Reinhard and Ceruti2005). As a result, sacred mountains and their significance within the Inca worldview have been classified hierarchically based on archaeological findings. For example, Antonio Beorchia Nigris’s 1985 book, El enigma de los santuarios indígenas de alta montaña, considered a key reference for the archaeology of high-altitude Andean sites due to its systematic compilation of available information, distinguishes between first-, second- and third-order mountains. In this classification, first-order mountains may contain sacrifices, figurines and ceremonial platforms, among other evidence, while second- and third-order mountains display less diversity and a reduced richness of elements deemed relevant to the Incas. Within our study region, five mountains can be classified as first-order. These are mountains located towards different cardinal points of Inca Viejo (Figure 3). To the north are Quevar (6130m asl), Acay (5950m asl) and Chañi (5896m asl); to the south Galán (5912m asl); and to the west Llullaillaco (6739m asl) (Beorchia Nigris Reference Beorchia Nigris1985; Reinhard & Ceruti Reference Reinhard and Ceruti2005, Reference Reinhard and Ceruti2010). Other sacred mountains of the second- or third-orders are also recognised to the east (Meléndez: 6020m asl), to the south (Ratones: 5252m asl; Archibarca: 5629m asl; Tebenquicho: 5830m asl; and Antofalla 6100m asl) and to the west (Aracar: 6095m asl; Arizaro 5764m asl; Macón: 5611m asl; and Socompa: 6180m asl) (Beorchia Nigris Reference Beorchia Nigris1985; Ceruti Reference Ceruti2003, Reference Ceruti2007; Leibowicz et al. Reference Leibowicz, Moyano, Ferrari, Acuto and Jacob2018; Vitry 2023).

Figure 3. The locations of sacred mountains mentioned in the text (figure by authors).

Regional comparison of archaeological evidence from sacred mountains

A summary of comparative evidence, including archaeological elements or indicators highlighted in previous sections, for Mount Inca Viejo and various sacred mountains from the Inca period is presented in Table 1. This includes references to the presence of ceremonial platforms or structures, monoliths, evidence of animal and/or plant remains, textiles, anthropomorphic and zoomorphic figurines, human sacrifices, kanchas, ceramics, associated mining records and Inca roads (Raffino Reference Raffino1981; Beorchia Nigris Reference Beorchia Nigris1985). Due to their importance in ceremonial contexts, the animal evidence is further separated to consider the presence of feathers and shell fragments from Spondylus, a marine bivalve of high symbolic value for the Incas that originates from the Pacific coast of Ecuador (Reinhard Reference Reinhard2006), nearly 3000km from the study region.

Table 1. Comparison between the archaeological indicators of Inca Viejo and different sacred mountains in the region. Features that are present on each mountain are indicated by an x.

* Located in Abra de Minas (near Inca Viejo). ** Only a human tibia was found on the summit.

All the mountains analysed in the study region have ceremonial structures (Beorchia Nigris Reference Beorchia Nigris1985), some of which may be considered ushnus (Reinhard & Ceruti Reference Reinhard and Ceruti2005; McEwan Reference McEwan, Meddens, Willis, McEwan and Branch2014). In the cases of Quevar and Inca Viejo, these structures feature stairs or ramps (Figure 4). At Quevar, the access ramp to the platform, flanked by walls, may have originally included steps; however, it has deteriorated considerably (Reinhard & Ceruti Reference Reinhard and Ceruti2005; Ceruti Reference Ceruti2007). The ceremonial structure at Inca Viejo, located on the entrance slope to the main chamber of the cave mine, boasts a staircase of 19 steps, delineated on both sides by double-row walls (López et al. Reference López, Coloca, Rosenbusch and Solá2018, Reference López, Coloca, Orsi, Araya, Seguí, Rosenbusch and Solá2020). This staircase shares construction characteristics similar to those recorded at the large Inca settlement of El Shincal, situated more than 200km south of Mount Inca Viejo in the valleys of Catamarca, Argentina (Raffino Reference Raffino1981; Giovannetti Reference Giovannetti2015).

Figure 4. Comparison between the ceremonial platforms of Inca Viejo (A) and Quevar (B) (figure by authors).

Inca Viejo and Quevar are also linked by the presence of monoliths, which hold considerable importance within the Inca worldview. These monoliths are associated with the representation of notable deities or ancestors in the context of offering and libation ceremonies conducted at ushnus (McEwan Reference McEwan, Meddens, Willis, McEwan and Branch2014; Meddens Reference Meddens, Meddens, Willis, McEwan and Branch2014). Various chroniclers mentioned the existence of these monoliths at the main ushnu in Cusco, the heart of the Inca Empire (Cobo Reference Cobo1956 [1653]; Pizarro Reference Pizarro1968 [1571]; de Acosta Reference De Acosta2008 [1590]). Generally, the stones are elongated and/or conical in shape with multiple smooth surfaces though they did not require a significant investment of labour (Figure 5A).

Figure 5. Archaeological evidence associated with Inca rituality at Inca Viejo and surrounding areas (figure by authors).

Monoliths have also been found on other sacred mountains in the region: Meléndez, Antofalla and possibly Galán (Beorchia Nigris Reference Beorchia Nigris1985; Leibowicz et al. Reference Leibowicz, Moyano, Ferrari, Acuto and Jacob2018). In more distant areas, they have been recorded on mountains such as Mercedario, Ascotán, Azufre, Tambillo and Misti (Beorchia Nigris Reference Beorchia Nigris1985). The recurrent presence of monoliths in sacred Andean mountains and their association with ceremonial structures or ushnus reflect their central role in Inca ritual practices (McEwan Reference McEwan, Meddens, Willis, McEwan and Branch2014; Meddens Reference Meddens, Meddens, Willis, McEwan and Branch2014).

Animal and plant remains are identified at almost all the sacred mountains in the study region (Table 1). Firewood is frequently found on or in the vicinity of the summit, while animal bones, particularly from camelids, have also been found at several sites and recorded offerings include the remains of various plant species, such as coca and corn. At Inca Viejo, corn (Zea mays), carob (Prosopis sp.), chañar (Geoffroea sp. decorticans/spinosa) and cebil (Anadenanthera colubrina) were recovered from inside the cave (López et al. Reference López, Coloca, Orsi, Araya, Seguí, Rosenbusch and Solá2020). Textiles of both plant and animal origin (e.g. twines, ropes) have also been identified at Inca Viejo (Seguí et al. Reference Seguí, Araya and Rucci2021), as has a Spondylus sp. bead (Figure 5B), which was recovered from an offering inside the cave. Spondylus shell has been identified at Quevar, Galán and Llullaillaco, first-order sacred mountains (Beorchia Nigris Reference Beorchia Nigris1985).

The role of feathers in the personal ornamentation of the Inca elites and as offerings in the form of mantles are described by Spanish chroniclers (e.g. Cobo Reference Cobo1956 [1653]; Pizarro Reference Pizarro1968 [1571]). Nearly 2000 feathers from both distant (eastern jungles) and local bird species were recovered from within Cueva Inca Viejo (Figure 5C). The jungle species include parrots and macaws (Psittaciformes), while local species include flamingos (Phoenicopteriformes), raptors (Falconiformes) and ducks (Anseriformes) found in the salt flats of the Puna. The feathers were recorded as offering mantles at the entrances to the secondary mining galleries, although many may have also been part of ornaments or headdresses, given the presence of ties made of vegetal and/or animal material (Seguí et al. Reference Seguí, Araya and Rucci2021). On Quevar, Chañi, Galán and Llullaillaco, feathers were used to ornament anthropomorphic figurines or chuspas (bags) (e.g. Reinhard & Ceruti Reference Reinhard and Ceruti2005, Reference Reinhard and Ceruti2010). Although no figurines were found at Inca Viejo, their presence cannot yet be ruled out as excavations are ongoing.

Discoveries of human remains at mountain summits generate considerable interest and it has been suggested that the Incas conducted human sacrifices as part of the capacocha rituals (Beorchia Nigris Reference Beorchia Nigris1985; Reinhard & Ceruti Reference Reinhard and Ceruti2010; Bachraty & Nautré Reference Bachraty and Nautré2023; Vitry 2023). To date, the discovery of human burials is rare among the sacred mountains of the Incas (Vitry 2023); in the mountains examined in this study, such burials have been recorded only on Quevar, Llullaillaco, Chañi and Acay (the latter containing just a human tibia). Yet, it is possible that there are burials at other sites that have not yet been found, so further excavations are required. In this context, the braids of human hair found at Cueva Inca Viejo (Figure 5D) are particularly pertinent, as these materials are typically associated with funerary contexts at other Puna sites (López Campeny Reference López Campeny2006/2007).

The presence of typical Inca architectural elements, such as kanchas, as well as ceramics featuring distinctive shapes and decorations, is not clearly recurrent across the analysed mountains (Raffino Reference Raffino1981). Nevertheless, these indicators are demonstrative and cannot be overlooked in this analysis, as they are crucial for characterising Inca occupations. The kanchas on Inca Viejo are located in the Abra de Minas enclave, a site where Inca ceramics, including globular vessels and plates with ornithomorphic handles, are particularly abundant (Figure 5E). Similar ceramics are found at first-order mountain sites such as Quevar, Llullaillaco and Chañi, where complete vessels associated with human sacrifices are also recorded (Reinhard & Ceruti Reference Reinhard and Ceruti2010).

Finally, several of the sacred mountains in the study region have been linked to mining and Inca roads. This relationship is seen at Quevar, Acay, Chañi and Meléndez (Raffino Reference Raffino1981; Beorchia Nigris Reference Beorchia Nigris1985; Leibowicz et al. Reference Leibowicz, Moyano, Ferrari, Acuto and Jacob2018), while either mining or Inca roads are observed independently at other mountains. In the case of Inca Viejo, mining is central to the analysis of the economic/symbolic role of this mountain for the Incas, particularly regarding the exploitation of turquoise, one of the most valuable minerals for the Empire’s elites (López et al. Reference López, Coloca, Rosenbusch and Solá2018). Various access roads lead to the main mine and an Inca road runs along the eastern slope in a north-south direction (Raffino Reference Raffino1981).