Tiwanaku (Spanish: Tiahuanaco) is a pre-Columbian ruined city in western Bolivia, in the southern basin of Lake Titicaca about 70 km west of La Paz, at roughly 3,800 m (12,500 ft) above sea level. It was the capital of the Tiwanaku culture, whose influence spread across the Titicaca region from about AD 600 to 1000 and fed its people from raised fields called suka kollus. The surviving monuments include the Akapana platform, the Kalasasaya enclosure with the Gateway of the Sun, and the precisely cut stone of Puma Punku. At its height around AD 800 the city covered about 4 km² and housed perhaps 10,000 to 20,000 people. UNESCO made it a World Heritage Site in 2000.
A capital at roughly 3,800 metres on the Altiplano
Tiwanaku is described as the highest state capital of the ancient world. The measured elevation at the Gateway of the Sun is about 3,825 m. Frost is endemic on the Altiplano, and away from the lake the plateau to the east is very dry. What made Tiwanaku possible was water: Lake Titicaca keeps the basin a little warmer and more humid than the open plateau, and the Tiwanaku and Katari rivers supplied the water for its farmland.
The site lies in a valley between two mountains that Andean tradition treated as sacred, Pukara and Chuqi Qʼawa, and the Akapana appears to have been aligned with the peak of Quimsachata. The people who built it left no writing, so the city’s own name is lost. The Jesuit chronicler Bernabé Cobo recorded an older name, taypiqala, Aymara for “stone in the centre”, and the researchers Heggarty and Beresford-Jones suggest the city’s own language was most likely Puquina rather than Aymara.
A statistical assessment of the reliable radiocarbon dates puts the founding at around AD 110. Between roughly 450 and 550 other large settlements in the southern basin were abandoned, leaving Tiwanaku as the main centre, and from about 600 the city grew quickly. William Isbell describes a dramatic transformation between 600 and 700 that set new monumental standards. Its influence reached the Moquegua Valley in Peru, about 150 km from the lake, and the Azapa Valley in Chile, carried by llama caravans rather than armies: there is no defensive architecture at any Tiwanaku site.
Suka kollus: raised fields between the Katari and Tiwanaku rivers
The food base for this high city was a system of raised fields, known in Aymara as suka qullu (often written suka kollu). Farmers built long planting platforms, 5 to 20 m wide and up to about 200 m long, separated by shallow canals filled with water. In the Katari and Tiwanaku valleys these fields covered as much as 130 km².
The design dealt with the Altiplano’s worst problem, frost. The water in the canals absorbed heat from the strong high-altitude sun during the day and gave it back at night, wrapping the crops in slightly warmer air. Algae and silt in the canals were dug out as fertiliser, and the canals could hold fish. The main crops were potatoes and quinoa, with llama herding and lake fishing alongside; potatoes and meat were freeze-dried or sun-dried to keep through the lean months.
The University of Chicago archaeologist Alan Kolata and his Bolivian colleague Oswaldo Rivera, who excavated at Tiwanaku from 1978 into the 1990s, rebuilt experimental suka kollus in the 1980s and rediscovered how they worked. When a freeze hit in 1988, it killed 70 to 90 percent of the plants in ordinary control plots, while production in the raised fields fell by only about 10 percent. Average potato yields compared as follows.
Not everyone accepts that the fields were so productive in practice. The archaeologist Bandy argued in a 2005 study that local farmers dropped the method once the development programmes ended in the 1990s, and that the fields are vulnerable to potato parasites. One alternative view is that their value lay in timing: raised fields could be planted and harvested early, allowing two harvests a year, one of them used to host the feasts that drew labourers to the capital.
The Akapana platform and its looted summit
The largest monument at Tiwanaku is the Akapana, a terraced platform mound in the shape of half an Andean cross. It measures about 257 m across, 197 m at its widest point the other way, and stands 16.5 m tall. A sunken court seems to have occupied the top, but a deep looters’ trench cut from the centre to the eastern side has nearly destroyed it, and the spoil was dumped down the east face.
Excavations on the Akapana found sacrificial dedications of both humans and llamas or alpacas, and some researchers argue it doubled as an astronomical platform. Its recent history shows how easily the site can be harmed. In 2009 a state-funded restoration that faced the mound with adobe was halted after UNESCO complained that there was no evidence the original had looked like that.
Kalasasaya and the Gateway of the Sun
North of the Akapana lies the Kalasasaya, a rectangular courtyard more than 90 m long enclosed by walls of tall stone pillars with smaller blocks between them. Its largest single stone weighs about 27 tonnes. Looters had stripped out the filler stones, leaving only the pillars, which is why the American traveller Ephraim Squier called it the “American Stonehenge”. The walls seen today were largely rebuilt by the Bolivian government in the 1960s, a reconstruction that archaeologists consider poorly supported by evidence. The enclosure is positioned to frame the sunrise at the equinoxes and solstices. Just east of it is the Semi-Subterranean Temple, a sunken court whose walls are studded with carved stone heads.
Inside the Kalasasaya stands the Gateway of the Sun, carved from a single block of stone about 3 m tall and 4 m wide and estimated to weigh around 10 tonnes. When European explorers found it in the mid-19th century it lay on its side with a large crack running through it. It now stands where it was found, but researchers think it originally belonged to a series of gateways at Puma Punku. The frieze across the top shows a central figure in the Andean “staff god” pose, head ringed by 24 rays and holding a spear-thrower. Rows of 48 smaller figures run towards it: 32 with human heads and 16 with bird heads, the outer ones added later than the core 30. Some scholars link the central figure to the creator god Viracocha or the Aymara weather god Thunupa; claims that the frieze is a calendar remain unproven.
Puma Punku’s cut andesite and sandstone
About a kilometre from the Kalasasaya is Puma Punku, “Gate of the Puma” in Aymara and Quechua. It is a T-shaped terraced platform mound 167 m by 117 m and 5 m high, begun some time after AD 536 and probably never finished. On its eastern edge the Plataforma Lítica, a stone terrace about 39 m long, holds the largest block at Tiwanaku: a red sandstone slab 7.8 m long and 5.2 m wide, estimated at 131 tonnes. A second slab weighs about 85 tonnes. Petrographic analysis traces this sandstone to a quarry near the lake roughly 10 km away.
The smaller, more finely worked facing blocks and carvings are andesite, brought from quarries on the Copacabana Peninsula about 90 km away across Lake Titicaca. Fragments of at least five andesite gateways similar to the Gateway of the Sun lie around the platform, along with miniature models of gateways. The architectural historians Jean-Pierre Protzen and Stella Nair noted flat faces and sharp interior right angles that hammerstones alone could not produce. Nair later reproduced a small section of carving with stone tools of flint, obsidian and similar materials in about 40 hours; bronze tools proved nearly useless on andesite. The precision has attracted claims of ancient alien builders, which have no support. Much of the damage is human: later generations quarried the site for building stone and railway ballast.
Drought, destruction and the end around AD 1000
Around AD 1000 production of Tiwanaku pottery stopped, and within a few decades both the urban core and the largest colony at Moquegua were abandoned. The raised fields stayed in use somewhat longer, which is why some sources extend the end date to 1150.
For decades the leading explanation was drought. Kolata’s team argued that falling rainfall dried out the raised fields, the food surplus collapsed and elite power went with it; research by the geologist Elliott Arnold of the University of Pittsburgh found evidence of greater aridity around the time of the collapse. Newer, more refined chronologies challenge this and suggest the drought did not start until after the decline, which gives more weight to internal social causes. There are clear signs of deliberate destruction: monolithic gateways, including the Gateway of the Sun, were toppled and broken, and the Putuni complex was burned with its storage jars smashed. One proposal links the dispersal of Tiwanaku’s people to changes in Mapuche society far to the south, including Puquina loanwords in the Mapuche language.
Tiwanaku since 2000: UNESCO listing and the hidden city
The Spanish soldier and chronicler Pedro Cieza de León was the first to describe the ruins in writing, in 1549. UNESCO inscribed them in 2000 as “Tiwanaku: Spiritual and Political Centre of the Tiwanaku Culture”. A drone survey in 2016 revealed previously unknown buried structures spread over 411 hectares, including a stone temple covering 17 hectares, so far more of the city lies underground than above it.
The Inca, who reached the Titicaca basin centuries later, treated Tiwanaku as the place where the world was created, and they borrowed from its stonework and imagery; their own story is told in this guide to the geography of the Inca Empire. The lake that made the city possible is covered in detail in our Lake Titicaca geography article, and Tiwanaku sits within the larger picture of the Altiplano, the Andes and the lowlands described in the Bolivia country guide.