Scientists have discovered the remains of a sprawling network of mysterious ancient cities in the Amazon that may revolutionise our understanding of human civilisation in the world’s largest tropical rainforest.

A little-known culture built arrow-straight roads and canals through thick jungle to connect urban settlements where they ate sweet potatoes and drank beer, excavations have found.

The settlements, resembling the Maya’s “garden cities” and which date from around 500BC, are the largest and oldest of their type, suggesting the mysterious Upano people predated the Mayans, Incas and Aztecs in the pre-colonial Americas.

We’re aware of the technology used to find those ruins, giant space lasers measuring the height of the ground from orbit Buck Rogers stuff. Indeed, one of us has used it to find slag piles from medieval mining.

However, the bit that surprises us. There have been a number of these finds of civilisational ruins inside what is now the Amazon jungle. Vast areas of land underlaid with biochar as well - effectively charcoal mixed into the soil.

The implication of which is that the Amazon rainforest - or at least large patches of it - is not something that’s been pristine these past 10,000 or 12,000 years. Rather, large parts of it have been cut down for framing, or burnt for that charcoal. Since when the forest has regrown.

That the Amazon rainforest can regrow, our proof being that it has, seems to be a fairly important fact to us. So we’re surprised that we’ve not seen a swathe of stories explaining this at the same time as we have seen that swathe about these latest archaeological finds.

Hmm, what’s that? If it turns out the Amazon is replaceable then that kills a certain set of environmental stories you say? Ah, perhaps we’re not so surprised then.