High up in the Andes of Bolivia, there are the ruins of the city of Tiahuanaco, the greatest mystery in the Andes. At over 4,000 metres above sea level, it is at a higher altitude than even the highest European mountain. It seems a strange site for a city – and yet over millennia, a series of cities have been built there. And no-one knows who built them!

Older than the Incas

When the Spanish became the first Europeans to reach the South American Andes, they found the ancient Incan civilisation ruling Peru and Bolivia. The Incans had held power for hundreds of years, and built great cities.

And yet, when they were asked about Tiahuanaco, the Incas said they didn’t know who built this ancient city. It was already in ruins and abandoned when they first reached the area. Even the local natives could not tell the Spanish who built Tiahuanaco.

And in the 500 years since then, despite the advance in archaeology, we are none the wiser. Critically, there are no written records in Tiahuanaco, that we can read – only mysterious grooves on some statues and stones that could be some sort of writing, or just decoration!

How old is Tiahuanaco?

An exclusive programme of over 500 test pits in the 1950s found that the city existed in 3 phases over 1,400 years.

About 200BC, the first primitive town was built.

Then within 200 years, the large village had become a larger town, with stone buildings.

By the end of the 4th century AD, the city had grown enormously and entered its “imperial” phase, with massive buildings, extensive suburbs and looking like the capital city of a large empire.

But by the 13th century, the city had been abandoned. When the Incas came to the area 100 years later, they were astonished to discover his huge city, as they had no idea it had existed or who built it.

The Imperial phase led to massive rebuilding of the city, laying it out with formal streets and large public buildings and temples – in the same way as many Empires rebuilt their capital cities.

And this leads to the other big mystery.

How was Tiahuanaco built?

The Imperial phase of Tiahuanaco involves enormous constructions works, with many statues up to 10 metres tall and buildings using single building blocks weighing up to 100 tonnes.

And yet there were no stone quarries here. In fact, when experts analysed the building stone used in the city, they found that most of I cam from quarries tens of kilometres away. Some stone even came from quarries on an island in the middle of Lake Titicaca.

How were huge stones transported these long distances – and why?

It’s still not clear. At this time in South America,  there were no horses or oxen being used to drag anything, let alone the massive stones that needed to travel over mountains and valleys.

And how did the people lift these colossal stones up into the air to place them high up in building walls?

We still don’t know the answer!

The mysterious White God Con-Tiki Viracocha

The final mystery of Tiahuanaco is about their most important god. Memories of this god survived the fall of the city, so the story of the god CON TIKI VIRACOCHA is known and we recognise carvings of him in Tiahuanaco.

Viracocha was said to be white-skinned and bearded, and was worshipped in the first millennium AD, over 500 years before the first Europeans reached this area.

And the beard is strange, as it is a full European-style one, a type native South American tribes could not do.

So how could the mysterious inhabitants have a god of European appearance centuries before Europeans reached Latin America. In fact, this mystery goes well beyond Tiahuanaco, as pale-skinned, blue-eyes and full-bearded men were also worshipped in Central America and other parts of South America too.

Yet another Tiahuanaco mystery we can’t explain!

NOTE – if you think the name Con-Tiki sounds familiar, the explorer Thor Heyerdahl named a boat that when he built it to try to prove his theory that ancient people travelled from South America to Easter Island and beyond.