Recent Research

Our research at Tambo Viejo comprised the excavation of two structures, both adjacent to Plaza 2 (Figure 1b). They were selected because of their location next to an Inka public space. Structure 1 (Figure 2a and Supplemental Figure 1) is a large rectangular building that extends almost the entire length of the southern side of Plaza 2, whereas Structure 2 is a much smaller building found across from Structure 1. The walls of the buildings consist of two alignments of cobblestones, set in mud mortar and plastered to create a smooth surface. The finding of large rectangular adobes at the surface level suggests that the stone base of the walls had been topped with adobes that had collapsed over time.

Figure 2. Map of Structure 1 (a) and of Structure 2 (b).

Although the occupation of the site was brief, there was a substantial change in the configuration of the structures. The final layout of Tambo Viejo was established only after several changes had been made. At the time the final layout of Structure 1 was established, other earlier walls had been demolished or substantially altered, leaving behind only small, poorly preserved wall segments; in some instances, the only evidence that remained was the mud mortar placed at the base. Consequently, it is difficult to determine the initial wall layout and the shape of the earlier structures.

These early constructions, most of which were demolished, were covered and sealed by a clay floor that is associated with new walls that represent a second stage of construction. It was during this stage that Structure 1 was divided into three parts with the construction of two north–south aligned walls in the middle section of the building. The eastern and western divisions were about the same size, whereas the central division was much smaller. Moreover, at the northern side of the western and central divisions, a corridor—1 m wide and maintaining an east–west alignment—was built. All these new additions greatly modified the layout of Structure 1.

The final modifications before the abandonment of Tambo Viejo were made only inside the central division. First, a small square enclosure was established along the middle section of the western wall. Immediately to the north of the enclosure, there was a small staircase leading toward the top section of the enclosure. It was impossible, however, to determine the entrance of the enclosure because the upper segments of the walls had been demolished. A second construction was also carried out immediately to the southwest of the square enclosure; it consisted of an L-shaped wall that was joined to the eastern wall of the central division. With these additions, the space inside the central division became narrower, suggesting that access to this section of the building may have become restricted.

At the time that Structure 1 was divided in three parts, several large-size ceramic vessels were placed near the main walls. They were placed in a vertical position, with their bases buried in the sterile formation and their openings at the floor level. In two instances the vessels were covered with a piece of cloth and a cobblestone, indicating that they were meant to be reopened. Unfortunately, the contents of the vessels had been looted, making it difficult to assess their function.

In addition, two stone-walled cists were built inside Structure 1, at the south side of the central division. The walls of the cists were built of a single alignment of cobblestones set in mud mortar; their openings were also at the floor level. The cist found at the southwest corner of the central division, at floor level, is almost square in shape and 1 m deep. The second cist found inside the second division is smaller, with an oval shape at floor level and 70 cm deep. Maize grains were found in the first cist, but the other cist was empty. Finally, another small structure of almost circular shape and 1.25 m deep was found inside the eastern division. At the base level we found ash and charcoal, in addition to partially burned camelid bones and sweet potatoes that indicate this structure functioned as an earthen oven.

Structure 2 (Figure 2b) is smaller than Structure 1 and is found north of Plaza 2. A cobblestone wall divides the building into two parts: north and south. The south division is further subdivided into two parts (east and west). The west subdivision provides information about the construction activities carried out at this building. Indeed, it was at this section that a sequence of three floors was determined (Supplemental Figure 2). The first floor was built directly over the sterile formation. About the same time, a small compound to house guinea pigs was built at the northeast corner of this division. The most recent floor, placed directly above the oldest floor, consisted of cobblestones deposited to seal the floor and the guinea pig hut. Over the cobblestones, a fill of dirt mixed with ash and burn material was deposited in preparation for the establishment of a second floor. Over the new floor we found a good concentration of material remains, indicating intensive activity. Finally, the second floor was sealed by an accumulation of fill, over which the last floor was built. About the same time, an elevated platform with a clay floor was established at the east section of the south division. This floor appears to seal earlier constructions, but excavation did not continue beyond the clay floor.

At the north division of Structure 2, it was possible to determine the superposition of two floors. The first floor was built right over the sterile formation, whereas the second was built over a fill that sealed the first floor. At the southwest section of this division, a small offering was placed just before the second floor was established. The offering consists of a deposition of maize cobs, some clearly burned, over which a small (13 cm) clay figurine was placed facedown (Figure 3a). At the eastern side of this division an old wall was partially uncovered. The wall was sealed by the second floor, which is associated with another cobblestone wall established at some point before the site was abandoned.

Figure 3. (a) Clay figurine from Structure 2N; (b) adorned guinea pig from Structure 1W, Unit 31; (c) llama offerings from Structure 1C. (Color online)

The excavation of the two structures demonstrates that, despite the apparent short duration of Inka occupation of Tambo Viejo (Supplemental Figure 3), the site underwent substantial change. The final layout of the site was the result of several modifications. It appears that both structures, but particularly Structure 1, were originally spacious buildings, fashioned perhaps to accommodate a substantial number of peoples (mita workers?) who likely came to establish the Inka center. Once the main constructions were built and a large number of workers was no longer needed, the shape and size of both structures were modified. As discussed in the following section, Inkas performed a series of ritual activities to legitimize the construction.

The Offerings

Various types of offerings and evidence for feasting were uncovered at the site. Offerings were deposited throughout the Inka occupation and indicate the importance of ritual celebrations. One set of offerings consists of agricultural products, such as lima beans (Phaseolus lunatus), achira (Canna edulis), sweet potatoes (Ipomoea batatas), chili peppers (Capsicum sp.), and maize (Zea mays). A second set of offerings, placed throughout the buildings, consists of intact guinea pigs. Several of the guinea pigs were naturally mummified. This excellent preservation enabled us to determine that, in preparation for the rituals, many of the animals were adorned with long and colorful wool strings inserted in their ears and wrapped around their necks. The rodents were carefully placed on the ground, some facing east, and covered with clean sand. Some of these animals were carefully enveloped with a piece of cloth.

Moreover, food was prepared at a center location of the western division of Structure 1 (Unit 26). A circular earth oven, resembling a contemporary pachamanka, was established directly over the sterile formation. At the base of the oven there was an accumulation of charcoal. Around the cobblestones that formed the top portion of the oven we found an accumulation of achira leaves. Ethnographically, it is known that achira leaves are placed directly over the heated oven, over which food is deposited. Then, over the food, a second layer of achira leaves is placed as a cover, and finally the entire oven is buried with dirt. An AMS measurement for this context produced a date of 410 ± 15 BP (UCIAMS-211254; wood charcoal; D¹⁴C = −50.1‰).

When the oldest floor was replaced, additional guinea pig offerings were buried. Some of the guinea pigs were also adorned with colorful strings (Figure 3b). The similarities in guinea pig adornments suggest that the rebuilding process took place within a relatively short period.

Finally, about the time the last changes were made at the center division of Structure 1, new offerings consisting of four intact (naturally mummified) young llamas were deposited (Unit 64). The llamas were facing east; the northernmost llama had brown fur, and the other three had white fur. Cobo (Reference Cobo1990 [1653]:113) noted that brown llamas were sacrificed to Viracocha and white llamas to the Sun.

In preparation for the rituals, the young camelids were decorated with long, colorful wool strings attached to their ear tassels and with colorful necklaces placed around their necks. Once adorned, the limbs of the camelids were flexed toward their bodies and tied with a rope. The securely tied llamas were placed side by side facing east (Figure 3c), in pits excavated by breaking the hard clay floor that represented the last occupation. Just before the animals were covered with sand, a guinea pig was placed above the neck of the white camelid found next to the brown camelid, and a 11 cm long stick with an orange feather attached at one end was placed in a vertical position near each eye of the white llamas. Around the nose and mouth of the three white camelids there was a hardened sand formation, suggesting that the llamas may have been buried alive.

Next to the llama offerings there were two additional empty pits; before excavation several newborn/subadult camelid bones were found in the area near the camelid offerings. This suggests that the offerings had been looted and that the original number of sacrificed llamas likely was higher than the four llamas reported here. Finally, around the camelid offerings there were several small pits: some were found to be empty, but others contained maize, lima beans, guinea pigs, and a small package of lime (used for coca chewing).

Concluding Comments

The recent research carried out at Tambo Viejo demonstrates that intensive construction activity took place at this site. The Inka state invested a considerable amount of energy and resources in establishing this center; it is possible that this was an unfinished project and that the existing layout may not be what the Inka envisioned. Moreover, the construction of Tambo Viejo also resulted in the placement of various types of dedicatory offerings, some of which are unprecedented. Inka offerings indicate that the incorporation of the Acari Valley was more than just an act of taking over the valley and establishing control over its indigenous inhabitants: it seems that the Inka performed ritual celebrations in order to normalize their presence and legitimize Inka expansion.

Both excavated structures were originally designed as large spacious buildings. Structure 1 perhaps functioned as a callanca, likely established to accommodate the substantial number of people who came to build Tambo Viejo. Structure 2 perhaps functioned as a domestic unit, as indicated by the presence of abundance ash and domestic residue. Subsequently, the function of both structures changed. The presence of spinning tools and balls of yarn inside Structure 2 suggests that textile production was conducted there. It remains unclear what may have been the functions of the eastern and western divisions of Structure 1, although the presence of large ceramic vessels suggests that perhaps chicha was produced there. The central division of Structure 1 exhibits a better-preserved floor and indicates that access to this section of the building was limited, perhaps because of the presence of a storage cist.