Pachacamac Archaeological Project
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ACKNOWLEDGEMENTS: Information and images presented in this website were obtained with the support of National Science Foundation grants BCS-0313964 and BCS-0411625 and National Geographic Society CRE grants 7472-03 and 7668- 04. We gratefully acknowledge their support.

Research Issues and Aims:

What underwrote the longevity and resilience of Pachacamac in the face of the political, religious, and environmental upheavals that beset much of the Andes during the last 1500 years of prehistory, including the influence or intrusion of powerful polities such as the Wari, Sicán, Ychsma and Inca? Ethnohistorical documents and iconographic studies have shed light on the nature of Pachacamac religious ideology (e.g., Dulanto 2001;Jimenez 1985; Menzel 1977; Patterson 1985; Rostworowski 1992, 1999). However, the human dimension of Pachacamac, particularly of the pre-Inka era, has not received attention it deserves. Who lived at and maintained the site? What roles did they play? Were residents members of the dominant local political group? Was the site always a largely vacant pilgrimage center? Did the ebb and flow of the site and its extra-local significance relate to environmental conditions?

Many of these basic questions have not been addressed in any systematic manner, in spite of a century of archaeological investigations (see Shimada 1991 for review). The general fame and the number of archaeological projects conducted thus far might give the impression that we have an in-depth understanding of the site and its institutions and population. However, nearly all have been inadequately published and/or limited in research scope, scale, and duration, and been overly concerned with highly visible, late pre-Hispanic monumental, elite and/or religious constructions (e.g., Eeckhout 2000; Franco 1998; Franco and Paredes 2000; Jímenez 1985; Paredes 1985, 1988; Paredes and Franco 1985, 1987). In spite of these advances in our understanding of monumental structures and associated priests and lords, little has been known of the common people. In essence, conception of the site as a dynamic, integrated whole and concern for its social dimensions have been sorely missing.

Thus, our project began in 2003 with the long-term aims of (1) defining the identity, composition, organization, roles and dynamics of the pre-Inka residents, (2) through this clarification of the social dimensions, gaining an understanding of how this religious center maintained itself, exerted its influence, and successfully negotiated political and environmental stresses for so long, and (3) determining whether it really was merely a pilgrim and burial center as has been often assumed or had a more urban, multi-functional character.


The 2003 fieldwork being the first season of our project was geared toward establishing a sound basis for more focused examination of various facets of the social foundations. The two specific aims and attendant methods were

  1. Preparation of a detailed digitized map of the site using airphotos taken in 2000 and GIS techniques of on-screen digitizing (ArcInfo-ArcGIS softwares). All previous excavations and defined architecture will be located in the field and plotted on to the master map. Eventually we hope to produce a virtual 3-D model of the site.
  2. Definition of the location and extent of residential areas of different time periods through intensive surface survey of the entire site and subsequent ground-penetrating radar (GPR) survey and associated test excavations of selected areas. Any plans for extensive excavations at Pachacamac require effective strategies to cope with the scale of the site and accumulative effects of both cultural and natural site formation processes spanning at least the past 1200 years. GPR surveys and associated test excavations were thus proposed as a cost-effective strategy. GPR allows speedy, non-destructive survey of large areas, detection of diverse buried features, and pinpointing of possible excavation loci without extensive exploratory excavation (Clark 1996; Conyers 2000; Conyers and Goodman 1997; Shimadsa and Watanabe 1995). GPR is thus ideally suited for large, complex sites like Pachacamac, where dry, relatively homogeneous deposits allow detection up to 10 m below surface.
  3. Establishment of a comprehensive regional environmental history through deep sediment core analysis of the Urpay Wachak Lagoon (the goddess of fishermen; Rostworowski 1973) situated at the northwest corner of the site of Pachacamac. The cores are expected to contain pollens from local vegetation, lacustrine organisms (including diatoms that are single-celled algae with durable silica cell walls) and intermittent sediments washed down from the bluff by rains associated with infrequent, severe El Niño events. These contents and their stratification are crucial to the proposed research. For example, because individual taxa of diatoms have specific requirements and preferences in respect to water chemistry (salinity, pH, nutrient levels, and temperature), hydrologic conditions, and substrate characteristics, composition and relative frequencies of varied diatom taxa in archaeological context serve as sensitive indicators of the local environment (Juggins and Cameron 1999). Diatoms respond rapidly to local environmental change, as they have a short life cycle of a few days. In long sections they provide insights into changes associated with fairly drastic shifts in climate, moisture, leaching of soil, changes in land use or water quality.


The 2004 fieldwork continued our two-pronged, long-term effort to elucidate (1) the composition, role, and organization of the inhabitants who underwrote the daily operation, longevity, and power of Pachacamac, and (2) paleoenvironmental conditions that helped shape the nature, organization, extent and duration of human occupation of the site and its immediate surrounding.

For the first objective, we focused on Trench 1 excavation situated in the Pilgrims' Plaza just north of the Pachacamac Temple, widely regarded as the most revered temple at the site. This excavation that began in 2003 was expanded from the original 5x5 m dimension to 10x10 m so that the broader architectural organization and artifactual distribution could be better defined.

For paleoenvironmental reconstruction, the project team conducted a series of sediment coring at the Urpi Wachak Lagoon and an inferred well both situated near the Urpi Wachak Temple. Dr. Barbara Winsborough, diatom specialist, participated in the extraction and conducted a subsequent preliminary analysis of the extracted cores.


Continuing our long-term aim of elucidating the social foundations of Pachacamac (see above), we focused on the following specific task during our third season that spanned July to December, 2005:

  1. Definition of spatial and temporal variation in the occupation/use of the Pilgrims’ Plaza earlier indicated by ground penetration radar (GPR) surveys.
  2. Excavation of an apparent intact tomb detected during 2003 GPR survey in front of the Pachacamac Temple, and
  3. Analysis of artifacts and organic remains recovered during the 2004 and 2005 seasons.

In regard to the first aim, we were particularly interested in (a) defining the history and nature of occupation/use in the western half of the Plaza (at the base of the hill upon which the Inkaic Sun Temple stands) and (b) testing the possibility that the eastern half of the Plaza was compartmentalized into a series of functionally and/or socially discrete areas. Earlier GPR surveys showed a considerably less dense distribution of buried features in the western half. New survey in 2005 both confirmed the earlier findings of deep and densely distributed cultural remains in the eastern half of the Plaza, and revealed considerable spatial variation in their character and stratigraphy within the first two meters below surface. In essence, we wanted to test the hypothesis that the intensity of pre-Inkaic occupation/use of the area covered by the Pilgrims’ Plaza was inversely related to the distance to the Pachacamac Temple and the Old Pachacamac Temple; the closer the area to these temples, the greater the sacredness.

In regard to the second aim, we believe a comprehensive analysis of material and nonmaterial components as well biological and social aspects of funerary contexts is an effective means of elucidating the social foundations of Pachacamac.

The tomb excavation was also seen as an effective way to seek well-preserved Middle Horizon deposits. Earlier excavations in the Pilgrims Plaza had revealed disturbed Middle Horizon (Provincial Wari and Pachacamac) cultural deposits and underlying Early Intermediate Period (EIP) Lima adobito constructions ca. 1.5 to 2.0 m below surface. Construction of numerous sunken ritual enclosures and offering pits by the Ychsma people starting around A.D. 1100 had disturbed relatively thin Middle Horizon and EIP deposits, floors and walls. Given that the modern surface of the cemetery around the Pachacamac Temple is over 4 meters above the surface of the Pilgrims’ Plaza, we inferred that we would have a better chance of locating intact deposits of these periods under the cemetery surrounding the Temple. In essence, we had hoped to expose an inferred, intact tomb and pre-Ychsma deposits.