Puma Punku is part of a large ancient structure that forms part of the Tiwanaku site in Western Bolivia, believed to date back to around 536 AD.

It is a truly incredible feat of engineering. Some blocks of stone are more than 7 metres long, weighing more than 130 tonnes. Some are made of a type of red sandstone, which would have had to have been transported up a steep incline to reach the site, whilst other blocks, including the famous H-blocks, are made of the volcanic rock Andesite.

But a study from Joseph Davidovits, Luis Huaman and Ralph Davidovits, called Ancient organo-mineral geopolymer in South-American Monuments: Organic matter in andesite stone. SEM and petrographic Evidence, shows that far from being incredibly carved rocks, what we are looking at are two forms of ancient geopolymer concrete.

The andesite rocks contain organic matter, which is unheard of for a volcanic rock and therefore indicate it is made by artificial means. It may also mean that soon, the researchers may be able to Carbon-14 date the rocks of Puma Punku and we can finally have a good indication of just how old this famous site really is.