Tiwanaku

Tiwanaku (Spanish: Tiahuanaco or Tiahuanacu) is a Pre-Columbian archaeological site in western Bolivia, near Lake Titicaca, about 70 kilometers from La Paz, and it is one of the largest sites in South America. Surface remains currently cover around 4 square kilometers and include decorated ceramics, monumental structures, and megalithic blocks. It has been conservatively estimated that the site was inhabited by 10,000 to 20,000 people in AD 800.

The site was first recorded in written history in 1549 by Spanish conquistador Pedro Cieza de León while he was searching for the southern Inca capital of Qullasuyu.

Bernabé Cobo, a Jesuit chronicler of Peru, reported that Tiwanaku's name once was taypiqala, which is Aymara meaning "stone in the center", alluding to the belief that it lay at the center of the world. The name by which Tiwanaku was known to its inhabitants may have been lost, as they had no written language. Heggarty and Beresford-Jones suggest that the Puquina language is most likely to have been the language of Tiwanaku.

The dating of the site has been significantly refined over the last century. From 1910 to 1945, Arthur Posnansky maintained that the site was 11,000–17,000 years old based on comparisons to geological eras and archaeoastronomy. Beginning in the 1970s, Carlos Ponce Sanginés proposed the site was first occupied around 1580 BC, the site's oldest radiocarbon date. This date is still seen in some publications and museums in Bolivia. Since the 1980s, researchers have recognized this date as unreliable, leading to the consensus that the site is no older than 200 or 300 BC. More recently, a statistical assessment of reliable radiocarbon dates estimates that the site was founded around AD 110 (50–170, 68% probability), a date supported by the lack of ceramic styles from earlier periods.

Tiwanaku began its steady growth in the early centuries of the first millennium AD. From approximately 375 to 700 AD, this Andean city grew to significance. At its height, the city of Tiwanaku spanned an area of roughly 4 square kilometers (1.5 square miles) and had a population greater than 10,000 individuals. The growth of the city was due to its complex agropastoral economy, supported by trade.

The site appeared to have collapsed around 1000 AD, however the reasoning behind this is still open to debate. Recent studies by geologist Elliott Arnold of the University of Pittsburgh have shown evidence of a greater amount of aridity in the region around the time of collapse. A drought in the region would have affected local systems of agriculture and likely played a role in the collapse of Tiwanaku.

The people of Tiwanaku held a tight relationship with the Wari culture. The Wari and Tiwanaku civilizations shared the same iconography, referred to as the "Southern Andean Iconographic Series". The relationship between the two civilizations is presumed to be trade based or military based. The Wari aren't the only other civilization that Tiwanaku could have had contact with. Inca cities also contained similar types of architecture Infrastructure seen in Tiwanaku. From this it can be expected that the Inca took some inspiration from the city of Tiwanaku and other early civilizations in the Andean basin.

The structures that have been excavated by researchers at Tiwanaku include the terraced platform mound Akapana, Akapana East, and Pumapunku stepped platforms, the Kalasasaya, the Kantatallita, the Kheri Kala, and Putuni enclosures, and the Semi-Subterranean Temple.