A wooden precursor to Stonehenge: oldest solar alignment

Ahead of the summer solstice, which falls on June 21 this year, new research pushes back the earliest known astronomical practice in the Stonehenge landscape. Work presented by archaeologists Phil Harding and Fabio Silva describes a timber monument on a hill about three miles east of the famous stone trilithons, where two posts appear to have marked the points of solstice sunrise and sunset. The find comes from a site near Bulford in Wiltshire and, by its dating, is roughly five centuries older than the stone circle itself.

It centres on two massive timber posts placed about 120 metres apart. Radiocarbon analysis of material from the pits that once held the posts gives an age of around 2950 BC. That places them in the late Neolithic, before the stone Stonehenge was raised nearby, with the main building phases of the stone monument usually dated to around 2500 BC.

What exactly does the alignment show?

The core of the research is geometry. Archaeologist Fabio Silva tested the orientation of the pair of posts using digital reconstructions and reports that the line connecting them matches the direction of sunrise at the summer solstice and sunset at the winter solstice, with a deviation he describes as accurate to within one degree. It is worth being clear about what the result is and is not. A match between the line and the solstice sun strongly suggests deliberate orientation, but the alignment alone does not prove how people used the space or what beliefs were attached to it.

The site that produced the find covers about 13 hectares and was excavated between 2015 and 2017. That work uncovered 48 pits holding pottery, animal bone and worked flint, pointing to repeated human presence over an extended period. In light of the new analysis, the timber monument is described as the oldest known solar alignment in the wider Stonehenge landscape.

Why does this matter for understanding the Neolithic?

If the orientation holds up in peer-reviewed form, the timber monument would move the start of documented solstice practice in this landscape to a time before the stone trilithons were raised. That would support the idea that interest in the sun’s movement along the River Avon did not begin with the stone monument, but that the stone may have inherited and reinforced an older tradition tied to timber, a material that rarely survives and so often slips out of the archaeological record.

The limits of this conclusion should be stated plainly. The wood rotted away long ago, so the posts are inferred indirectly from the pits that held them, and the dating carries the usual radiocarbon uncertainty. The alignment is drawn from a digital model rather than direct observation of a monument that no longer fully exists. No full peer-reviewed paper has yet been published that would allow independent checking of the method and its measurement assumptions, so the result should be read as a strong but still preliminary indication.

What the find does not claim matters as much as what it does. It does not tell us who raised the posts, how long they were used, or whether there was an unbroken link to the later builders of the stone circle. It does, however, raise a question worth following through coming excavation seasons: how many other timber monuments of this kind vanished from the record before we even learned to look for them?