About Cerro Baul: Empires of the Andes

The people huddled in their impregnable fortress atop the high mesa called Cerro Baúl, their last refuge as the mighty Inca legions swept through the valley far below. With its sheer walls and single, tortuous route to the top, the citadel defied attack by storm, so the Inca army laid siege to Cerro Baúl. For 54 days, the people held out. But with little food and no water, they found their redoubt was not only a grand bastion but also a grand prison.

Then, in hopes of saving their starving children, the defenders sent the youngsters down from the beleaguered mountaintop. The Inca received the children with kindness, fed them, and even let them take a few supplies to their parents - along with a promise of peace and friendship.

That was enough for the hungry and hopeless people of Cerro Baúl. They surrendered unconditionally to the new imperial order about A.D. 1475. The siege of Cerro Baúl was but the final chapter in the legendary history of what 500 years earlier had been the southernmost outpost of the Wari, the first of the great empires of the Andes. The Inca siege was described by Spanish chronicler Garcilaso de la Vega, and our two seasons of excavations at Cerro Baúl lend credence to this historical lore.

The mesa today is a sacred mountain, sanctuary of El Señor de Cerro Baúl, a spirit that's widely venerated throughout the region. But our investigations confirm that it was, for nearly five centuries, a majestic city that dominated the frontier between the Wari and the neighboring Tiwanaku empire.

The story of Cerro Baúl begins in the time archaeologists call the Middle Horizon, when the two empires ruled the central Andes. The Wari, secular and militant, governed most of highland and coastal Peru from their upland capitol at Ayacucho. The Tiwanaku, a trade-based state with a religious core, controlled parts of what is now Bolivia, southern Peru, and northern Chile from a capitol near Lake Titicaca. The Moquegua Valley, dominated by Cerro Baúl, is the only place where the two civilizations are known to have come face-to-face.

The Moquegua Valley had been in the Tiwanaku orbit until the Wari made their bold thrust into the region. To secure their political outpost, the Wari intruders strategically settled the towering Cerro Baúl and the adjacent pinnacle of Cerro Mejia. Unraveling the nature of this intruding colony and its relationship with the surrounding Tiwanaku is a long-standing concern of the Asociación Contisuyo, a consortium of Peruvian and American scholars investigating the region. Recent mapping and excavation at Cerro Baúl and adjacent sites are beginning to reveal pieces of this puzzle.

Where the two competing nations met, their citizens apparently chose cooperation over conflict. Our excavations find no evidence of warfare during the centuries (from about A.D. 600 to 1020) in which the Wari and the Tiwanaku shared the valley and its scant water. Goods and ideas almost certainly were being exchanged; interaction was inevitable, if for no other reason than to discuss rights to the most critical resource of the arid desert. Water streaming from mountain rainstorms had to pass by a Wari canal before it reached Tiwanaku fields.

Furthermore, we recovered a Tiwanaku-style kero (a drinking vessel used in ceremonies) among the Wari's most sacred ceremonial offerings yet found at the site - a strong argument for ritual interaction between the two groups who shared the valley.

Cerro Baúl was a bustling city of one- and two-story houses organized around plazas where people raised guinea pigs (for food and fuel), prepared feasts, created obsidian projectile points, and made necklace beads of turquoise, lapis lazuli, onyx, and polished shell imported from the Pacific coast. The 25-hectare (62-acre) summit of Cerro Baúl - some 600 meters (nearly 2,000 feet) above the valley floor - was clearly the political and social crown of the Wari outpost. Yet most of the empire's citizens lived not on the top, but on terraces cut into less lofty heights.

When the Wari arrived in the valley, they introduced an agricultural technology of terracing steep slopes and digging long, serpentine canals across the broken land. A 10-kilometer (6.2-mile) canal wound from the Torata River through the El Paso Divide between Cerro Baúl and Cerro Mejia, where the water course split to irrigate expansive terraces that stairstepped the flanks of both hills. This high-country irrigation system may be the key to the Wari's successful expansion into the extremely arid Moquegua Sierra, especially during severe droughts from A.D. 562 to 594 and from A.D. 650 to 750.

The summit of Cerro Baúl is divided into two areas of very different architecture. A monumental core comprises one- and two-story masonry buildings, while the eastern occupation, extending to the edge of the mesa and overlooking the route of ascent, is crowded with more modest, one-story stone dwellings similar to those found on the terraces of the slopes.

Building atop the mesa was a daunting task. Earth for mortar and silt for plaster came from the banks of the Rio Torata, two hours away by foot. Water for mixing those materials was hauled uphill from the El Paso canal. For construction stone, Wari builders turned to the mesa itself, quarrying the western half of the summit so heavily that it resembles a cratered lunar landscape.

Fine masonry construction was restricted to important buildings that adhered to the strict architectural canons of the imperial capital at Ayacucho. D-shaped structures are among the rarest and most distinctive buildings at the political nexus, where they likely were at the sacred center of Wari culture, an area of sacrifice and propitiation of the gods. At Cerro Baúl, we find at least one and possibly two of these temples. In our investigations of one of them, several fine artifacts were found in a ritual offering. These include entire polychrome ceramic vessels, an engraved gourd bowl, and a silver-alloy foil camelid 2.5 centimeters (about an inch) across.

Another potentially important religious complex at Cerro Baúl is the plaza of the sacred stone, an architectural compound built around a large boulder at the center of the summit. Sacred stones were prominent features in Inca cosmology, and a similar structure has been uncovered near the Wari site of Pikillacta in the Cuzco region. These stones were the centers of ritual and received offerings of special libations (such as maize beer or sacrificial blood) or of sacred items. Common Inca sacrificial offerings included llamas, coca leaves, gold or silver work, and in extreme cases, human children. The massive boulder of Cerro Baúl likely played a similar role.

The most common architectural form at the capital and other Wari cities is an enclosed plaza flanked by impressive stone halls. These halls included residences of governors and wealthy citizens, government offices, and beer houses for state-held parties that rewarded the loyalty of important subjects. The most interesting of the long halls that have been excavated so far contained a burnt deposit of classic vessels and keros, some of which were decorated in a hybrid Wari-Tiwanaku style. Six fine necklaces were also recovered from this burnt offering. Each had an average of 970 shell beads, some with a few lapis lazuli or chrysocolla tube beads as well. The evidence suggests the fire that destroyed the hall was intentionally set, and the beautiful ceramic vessels, many of them probably brought more than 500 miles from the Wari capital, were deliberately smashed and thrown into the smoldering flames.

The fire and destruction clearly were ceremonial and not a general sacking of the site. As part of the final sacramental drinking episode in this hall - perhaps as part of the abandonment of Cerro Baúl itself - Wari priests ceremonially interred the building. The offering of bead necklaces was made after the fire had been extinguished.

Similarities in their religious iconography are impressive and suggest intimate contact between the Wari and Tiwanaku. The Tiwanaku influence on hybrid Wari keros reflects the incorporation of Tiwanaku ideas in the highest realms of Wari religion, and the existence of a Tiwanaku-style kero in the most sacred of Wari ritual offerings on the summit documents the inclusion of Tiwanaku artifacts in Wari religious ceremonies.

By studying relationships between the Wari and the Tiwanaku, we can observe how ancient empires communicated with each other. In our own age of internationalization and globalization, the Andean past may tell us a great deal about the nature of confrontation between nations and the successes and failures of strategies of imperial interaction and control.

PATRICK RYAN WILLIAMS is visiting Assistant Professor of Anthropology at the University of Florida. Educated at Northwestern University and the University of Florida, he has directed the Cerro Baúl Excavation Project since 1997.

MICHAEL E. MOSELEY is Professor and Associate Chair of Anthropology at the University of Florida. Educated at Berkeley and Harvard, he was a founding member of the Asociación Constisuyo and has conducted archaeological research in the Andes for more than 30 years.

DONNA J. NASH is a doctoral candidate at the University of Florida. She is currently directing excavations at the site of Cerro Mejia and is a Supervising Archaeologist on the Cerro Baúl Excavation Project.