In South America, cultures of the Andes mountains and the Pacific coast built cities, roads and irrigation, and made superb pottery, textiles and goldwork. In North America, peoples of the Southwest and the Mississippi valley built villages and towns of stone and earth.
Looking closely: Machu Picchu. The Inca ruled the largest empire in the Americas from Cusco. Machu Picchu was probably a royal estate for the emperor Pachacuti, built around 1450 on a ridge high above the Urubamba River, with the peak of Huayna Picchu rising behind. Terraces step down the slopes for farming and to hold the soil. Inca masons fitted the stones of the finest walls without mortar, so tightly that a knife blade will not slip between them, and they tilted walls and doorways slightly inward, which helps them stand through earthquakes. The site was little known outside the region until the explorer Hiram Bingham publicized it in 1911.
Looking closely: A Moche portrait vessel. The Moche of Peru's north coast made jars in the shape of human heads, so lifelike that they seem to be portraits of particular men. This one has a strong jaw, a steady gaze and lines around the mouth, and wears a patterned headdress and big ear ornaments. The arched handle on top is a stirrup spout, a Moche specialty. Some were made in molds, so the same face could appear on several vessels.
Looking closely: Cliff Palace. Under a great overhang of sandstone, the Ancestral Puebloans built a village of shaped stone blocks set in mortar: about 150 rooms, square and round towers, and 23 kivas, round sunken rooms for ceremonies and gatherings. Tree-ring dates from its wooden beams show it was built mostly between about 1190 and 1260 and lived in until about 1280. Today it is part of Mesa Verde National Park.
Farther east, people of the Mississippian culture built Cahokia, near today's St. Louis, the largest town north of Mexico, at its height about 1050 to 1350. Its Monks Mound, an earthen platform about 30 meters high, is the largest prehistoric earthwork in the Americas.
Key idea
Why it works
Worked example: Why no mortar?
- The stones are shaped to fit tightly, and the walls lean slightly inward.
- In a quake the stones can shift a little and settle back without the wall collapsing.
- Mortared walls can crack and fall apart instead.
Answer: Tightly fitted, slightly tilted stones can move and resettle.
Common mistake