Of the many mysteries surrounding Stonehenge, one of the most puzzling is also the most enduring: How exactly did its ancient erectors move the site’s massive stones—each of which weights around 25 tons—nearly 150 miles?

Well, a group of Massachusetts-based researchers are now offering some clues that may help solve the age-old mystery.

This week, at the TED 2019 conference in Vancouver, the research firm Matter Design and the materials manufacturer CEMEX debuted a new series of hulking concrete forms—part interactive art installation, part scientific experiment—called Walking Assembly. Like the rocks of Stonehenge, each of Matter Design’s units weighs several tons—and each can also be moved with one hand.  

The project dates back to 2014, when Matter Design, led by scientist and MIT assistant professor Brandon Clifford, began looking into how prehistoric societies erected their megalithic structures. By using variable density concrete and calculating the exact center of a mass, Clifford and his team found that “structures that would otherwise rely on cranes or heavy equipment can now be intelligently assembled and disassembled with little energy,” according to the Matter Design website.

While potentially providing some answers to centuries-old questions, Walking Assembly might also give us a glimpse into the future. In theory, Matter Design’s formations can be used for large-scale architectural projects that, compared to most contemporary structures, would require less manpower to build and have a longer life expectancy.

The inner rocks of Stonehenge appear to have been dragged nearly 150 miles from where they were quarried to their current site. Photo: Matt Cardy/Getty Images.

But that’s not the only Stonehenge-related news to come out this week. A study published in the journal Nature Ecology & Evolution showed that the Neolithic peoples who occupied the region at the time scientists estimate the monument was built—3,000 BC—were descended from populations travelling from Anatolia (which makes up most of what is today Turkey).

Analyzing the DNA of human remains found across Britain, the researchers found that the ancestors of those who created Stonehenge traveled west from Anatolia, settling in Iberia before moving up to Britain around 4,000 BC.

The once-hazy picture of Stonehenge’s history is slowing becoming clearer. We now have theories as to who created the monument and how. The next and biggest question is why.