It is theorized the Pumapunku complex as well as its surrounding temples, the Akapana Pyramid, Kalasasaya, Putuni and Kerikala complexes functioned as spiritual and ritual centers for the Tiwanaku. This area might have been viewed as the center of the Andean world, attracting pilgrims from far away to marvel at its beauty. These structures transformed the local landscape; Pumapunku was purposely integrated with Illimani Mountain, a sacred peak that the Tiwanaku people believed to be home to the spirits of their dead. This area was believed to have existed between heaven and Earth.
The spiritual significance and the sense of wonder would have been amplified into a "mind-altering and life-changing experience" with hallucinogenic plants. Examinations of hair samples exhibit remnants of psychoactive substances in many mummies found in Tiwanaku culture mummies from Northern Chile, even those of babies as young as 1 year of age, demonstrating the importance of these substances to the Tiwanaku. As was characteristic of civilizations around this time, the Tiwanaku actively incorporated human sacrifice into their culture. The remains of dismembered bodies have been found throughout the area. Ceramic artifacts depict imagery of warriors, masked with puma skulls, decapitating their enemies and holding trophy skulls, adorned with belts of human heads with their tongues torn out.
Original Tiwanaku -Pumapunku complex.
The Middle Horizon Period extended from 600 – 1000 A.D. and once again the only other contemporary civilization of note was the Wari in Peru. The Tiwanaku Empire probably entered its most powerful phase in the 8th century AD. Many smaller towns or colonies were set up in the vast region under Tiwanaku rule. The most imposing monument at Tiwanaku was the temple of Akapana. It was a pyramid originally with seven superimposed platforms with stone retaining walls rising to a height of over 18 meters. Only the lowest of these and part of one of the intermediate walls survive intact. Investigations have shown that it was originally clad in blue stone and surmounted by a temple, as was customary in Mesoamerican pyramids.
Tiwanaku at its greatest territorial extent ca. 950 A D.
Sometimes called the Expansive Period, 700-1200 AD., it was a period of decline, with less elaborate pottery and fewer construction projects. The political dominance of Tiwanaku began to decline in the 11th century A.D., and the empire collapsed in the first half of the 12th century A.D. The reasons for this collapse are not yet understood. Scholars now reject invasion and conquest and attribute it to climatic change, giving rise to poor harvests and a progressive weakening of the central power to the point when it yielded to the pressures for autonomy from its components. Whatever took place the change had to be gradual there was no sudden ending, as many writers would like us to believe. People adapt and do whatever is necessary to keep on living. An example is the Maya, whose culture did not disappear suddenly -they just moved to another location where they could live as before.
More than likely one of the main reasons for the people abandoning the Tiwanaku area was the decrease in the water level of Lake Titicaca, which supplied water to their crops the suka kollas. These artificially raised planting mounds, which were separated by shallow canals, were filled with water that now was beginning to dry up. The canals could no longer supply moisture for growing crops, and the solar radiation they received from the sun during the day destroyed the plants. This happened gradually as the level of the lake slowly went down. Some estimate by as much as 50 meters by the end, and as one goes further east; the Altiplano becomes an area of very dry arid land. Therefore, abandonment by the vast majority was the only option.
Aerial View Tiwanaku Main Site (excluding Pumapunku)
After 1,000 AD, the empire collapsed and complete de-urbanization occurred by 1250 A.D. Localized raised field cultivation continued, but large-scale systems were not restored.
Complete Map of Tiwanaku Area
After the decline of Tiwanaku other Aymara societies emerged, politically organized, the most important kingdoms being the Lupaqa and Qulla. However, Tiwanaku was still used as a major religious place of pilgrimage, but no longer had a population that lived there or maintained it. This continued into Inca times and beyond.
Once satisfied that the humans were able to live and survive successfully. According the story, the Ancient Astronauts decided to “leave the land and go to the Pacific seacoast where they walked across the water until they disappeared.” Since Bolivia is a land locked country, they headed due west through Peru to the seacoast more than likely in a spacecraft.
Tiwanaku / Peru pacific seacoast
The word "Viracocha" literally means "Sea Foam." Therefore, this seems to be the end of the Ancient Astronaut intervention. However, this is not the end of the story of the people who had been the Tiwanaku who had to go on living with or without their help. The Ancient Astronauts probably left the area at the time the when Akapana Pyramid was being built. They may still have a space base hidden somewhere in the Andes Mountains today.