The 2004 Tiwanaku archaeological field season ended on August 26, when we held a ceremony with the workers, the local Aymara leaders, and the directors and archaeologists from Bolivia's Department of Archaeology. The season was a tremendous success, and we are already looking forward to next year.

Our primary objective for this project is to understand how the site's ceremonial core grew over time. Since Tiwanaku has been terribly damaged over the centuries, such understanding is uncommonly difficult to achieve. Substantial damage occurred to the site both during the Precolumbian period, when buildings were modified and torn down to make room for new ones, and after the European invasion, during which about 90 percent of the site's Colonial and later Republican stone constructions were destroyed. Nevertheless, we are pleased that, at this stage of our research, we have achieved a rough idea of how Tiwanaku's monumental sector grew. What we know is based partly on nearly a century of excavations. These interpretations, together with our findings, are presented in the following graphics. Notably missing from these reconstructions are everyday aspects of life such as the people's houses, the gardens, and the corrals for llamas and alpacas. Our graphics represent only a very idealized view of the monumental part of the site.

Construction of the Akapana Pyramid was made possible by razing previous ritual buildings, including sections of the Kalasasaya Complex, to provide the thousands of tons of stone necessary to build the pyramid, which became the largest freestanding structure ever seen in the high Andes. Yet the pyramid remained unfinished. Only when viewed from the east side did it appear monumental. Visitors were probably directed along a route carefully prescribed to impress, just as today, amusement parks and stage sets present only facades built to give the illusions of castles, store fronts, etc. In the sixteenth century, one of the first historians of the Andes exasperatedly summed up Tiwanaku: "They build their monuments as if their intent was to never finish them."

The huge stones scattered around the site even today create the same impression in the minds of modern visitors. Without traces of the lives of workers who must have guided visitors and plied them with food and entertainment, or others who must have decorated and even repaired the somewhat flimsy facades, our picture of life here at that time remains incomplete. Clearly, the purpose of the Tiwanaku was more than meets the eye, but for what, exactly, were these monuments intended? Answers to questions such as these will continue to be the focus not only for next season's archaeological work, but also for many generations to come.

Next Season!

We will continue in the 2005 season with our excavations and geophysical survey. The geophysical specialists from the University of Denver will be back, and we'll also be bringing aboard the GRASP laboratory at Penn and the CAST laboratory from Arkansas for what we call "data fusion": taking the images from multiple geophysical sensors and combining them into a single image. So far, the analysis of the geo-radar information at the University of Denver has surpassed our expectations (go to www.du.edu/~lconyer for a concise and easy to read description of radar survey and analysis.) We expected that the clay fill eroding from the Akapana Pyramid would make the entire area opaque to the radar, but instead the radar image reveals several interesting anomalies. A large diagonal line marks the modern tourist path, but to the south of that, we noted two structures, one superimposed on the other; the first structure in the highlighted square is a round or D-shaped form, and the second structure is a single rectilinear feature located a bit deeper. We'll be placing a trench to investigate both structures and to see how they relate to one another, and to the Akapana Pyramid. Geophysical survey will continue to further to the east, where the ground topography suggests the presence of more buried monuments.

For those wishing to read more about Tiwanaku, I recommend the recent publication by the Denver Museum of Art that accompanied their exhibition, Tiwanaku: Ancestors of the Incas. My own review of this catalogue can be seen in the March/April 2005 issue of ARCHAEOLOGY.