Although no one is certain whether it was the capital of a nation, Tiwanaku undoubtedly served as a great ceremonial center. At its height the city had a population of 20,000 inhabitants and encompassed approximately 2.6 sq km.
Some say the name roughly translates to ‘the dry coast’ or ‘stone in the center,’ and at 3870m (12,696ft) in altitude, the city most likely sat on the edge of Lake Titicaca, serving as the ceremonial center for the regions south of the lake.
While only 30% of the original site has been excavated – and what remains is less than overwhelming – the Tiwanaku culture made great advances in architecture, math and astronomy well before the Inca ascendancy.
Archaeologists divide the development of the Tiwanaku into five distinct periods, numbered Tiwanaku I through V, each of which has its own outstanding attributes.
The Tiwanaku I period falls between the advent of the Tiwanaku civilization and the middle of the 5th century BC. Significant finds from this period include multicolored pottery and human or animal effigies in painted clay. Tiwanaku II, which ended around the beginning of the Christian era, is hallmarked by ceramic vessels with horizontal handles. Tiwanaku III dominated the next 300 years, and was characterized by tricolor pottery of geometric design, often decorated with images of stylized animals.
Tiwanaku IV, also known as the Classic Period, developed between AD 300 and 700. The large stone structures that dominate the site today were constructed during this period. The use of bronze and gold is considered evidence of contact with groups further east in the Cochabamba valley and further west on the Peruvian coast. Tiwanaku IV pottery is largely anthropomorphic. Pieces uncovered by archaeologists include some in the shape of human heads and faces with bulging cheeks, indicating that the coca leaf was already in use at this time.
Tiwanaku V, also called the Expansive Period, is marked by a decline that lasted until Tiwanaku’s population completely disappeared around 1200. Were they the victims of war, famine, climate change or alien abductions? Nobody knows, though most archaeologists point to climate change as the most likely cause of the civilization’s rapid decline. During this period pottery became less elaborate, construction projects slowed and stopped, and no large-scale monuments were added after a few early examples.
At the request of Unesco, excavations of the site ceased in 2010. Archaeologists are concentrating now on preserving what they’ve already dug up. About 130,000 visitors come to the site every year.