Five thousand years of building in the Andes, from the platform mounds of Caral to the Inca empire: sunken plazas, adobe cities, terraces that remade mountainsides, and Inca stone walls fitted without mortar, with trapezoidal doors and niches.
Monumental architecture in the Andes is as old as in Egypt. At Caral in the Supe valley of Peru, around 2600 BC, people built large stepped platform mounds of stone and fill, with sunken circular plazas before them. Over the next three thousand years the coast and the highlands produced a series of distinct traditions: the stone temple of Chavín de Huántar (c. 900–200 BC) with its galleries threaded through the mass; the adobe pyramids of the Moche; Tiwanaku by Lake Titicaca (c. 500–1000), with precisely cut andesite and sandstone blocks joined by metal cramps and the monolithic Gateway of the Sun; and the vast adobe city of Chan Chan, capital of the Chimú.
The Inca, who expanded from Cuzco in the fifteenth century to rule an empire from Ecuador to Chile, drew on all of these. Their architecture is strikingly unified. Buildings are simple rectangles of one room, grouped round courtyards in enclosures (kancha), roofed with steep timber and thatch. What distinguishes them is the masonry and the handful of forms repeated everywhere: the battered wall, the trapezoidal doorway, window and niche, and the monolithic lintel.
Inca masonry ranges from fieldstone set in clay to the celebrated fine work of Cuzco. There are two fine kinds. Polygonal masonry, as in the great zigzag ramparts of Sacsayhuamán or the wall of Hatunrumiyoc with its twelve-angled stone, fits huge irregular blocks together without mortar, each ground to the shape of its neighbours. Coursed ashlar, as in the curved wall of the Coricancha, the temple of the Sun, lays rectangular blocks in level courses diminishing upward. In both, the faces are slightly pillowed so that every joint reads as a fine line of shadow. Stones were shaped by pounding with harder hammerstones and moved with ramps, ropes and levers.
The Inca also built on the scale of landscape: roads running some 40,000 km with suspension bridges of grass rope; agricultural terraces that turned valleys into staircases; and royal estates such as Machu Picchu and Ollantaytambo, where fine masonry and natural rock are worked together. Their walls resisted earthquakes that brought down later Spanish buildings; in Cuzco the colonial city literally stands on Inca foundations.