Puma Punku
High on the Bolivian plateau lie scattered stone blocks cut with such precision that some have claimed no ancient people could have made them.
What was reported
Puma Punku is part of Tiwanaku, a city near Lake Titicaca that was the centre of a powerful Andean culture around 1,500 years ago. Its ruins are a jumble of andesite and sandstone blocks, some with sharp inner corners, flat faces and repeated 'H' shapes that look almost machine-made.
Because the site is in ruins and its builders left no writing, it has become a favourite of television shows suggesting it was built with lost technology or help from beyond Earth.
Explanations offered
Archaeologists say the Tiwanaku people shaped the stones with harder hammerstones, sand and abrasives, using standard templates so that pieces fitted together. The repeated shapes show careful planning, not machinery. How they moved the largest blocks is debated, but ramps, ropes and large work crews are thought to explain it.
- When
- Built around 500–600 CE
- Where
- Tiwanaku, La Paz department, Bolivia
- Witnesses
- Archaeologists and visitors
- Status
- Mostly explained
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.