This 4,000-year-old wooden monument in England may have been built to ‘extend summer’, archaeologists say

Studies show that the ancient timber circle, dubbed “Seahenge,” was built in 2049 B.C. It was excavated from a salt marsh near a beach on England’s east coast in 1999. (Image credit: Holmes Garden Photos/Alamy)

A mysterious wooden monument buried beneath the Norfolk coast may have been built more than 4,000 years ago in an attempt to “extend summer” and bring an end to a prolonged period of bitter cold, according to a new archaeological study.The theory offers a fresh explanation for the prehistoric site known as Seahenge, one of Britain’s most unusual Bronze Age monuments. Rather than serving as a burial site or memorial, the timber circle may have been used for rituals intended to restore warmer weather during a time of severe climate stress, the study suggests.The research was published in GeoJournal and was led by archaeologist David Nance of the University of Aberdeen. By combining archaeological evidence with climate records, astronomy, folklore and environmental data, Nance argues that Seahenge and a second nearby timber circle were built as ritual responses to worsening weather around 2049 BC.“We know that the period in which they were constructed 4,000 years ago was a prolonged period of decreased atmospheric temperatures, and severe winters and late springs, placing these early coastal societies under stress,” Nance said in a statement.“It seems most likely that these monuments had the common intention to end this existential threat.”

A monument unlike any other

Seahenge, formally known as Holme I, was discovered after coastal erosion exposed its ancient timbers near the village of Holme-next-the-Sea on England’s east coast in late 1998.Local residents had known about the site for years, but it attracted attention after newspapers compared the circular structure with Stonehenge, giving it the now-famous nickname “Seahenge”.The monument consisted of an oval ring roughly 7.5 metres across, formed from 55 split oak trunks standing upright. At its centre stood a large oak tree stump that had been placed upside down with its roots pointing towards the sky. Inside the circle was a horseshoe arrangement of five larger oak posts. Not too far stood another timber monument, known as Holme II, built at around the same time and about 90 metres away.Dendrochronology, which dates timber by analysing tree rings, showed that the oak trees used to build both monuments were felled during the spring of 2049 BC.

Remnants of the ancient monument on a beach in Norfolk, England

An attempt to keep summer alive?

For years, archaeologists have debated why Seahenge was built.Some researchers suggested it commemorated an important person who had died. Others argued it may have been used for “Sky burials”, where bodies were left exposed for flesh-eating birds before burial.Nance believes the evidence points in a different direction.His study argues that the five-post horseshoe inside Seahenge appears to align with the sunrise at the summer solstice, the longest day of the year.According to the research, this alignment may not have been accidental.Drawing on British folklore, Nance suggests the structure symbolically represented a cage for a young cuckoo bird. In traditional belief, the cuckoo was associated with fertility and was thought to stop singing at the summer solstice before returning to the “Otherworld”, taking the warm weather with it.“Summer solstice was the date when, according to folklore, the cuckoo, symbolizing fertility, traditionally stopped singing” and returned to another realm, Nance said.“The monument’s form appears to imitate two supposed winter dwellings of the cuckoo remembered in folklore: a hollow tree or ‘the bowers of the Otherworld’ represented by the upturned oak stump at its center.”He suggests the timber circle may have recreated the mythical “pen” described in folklore to keep the cuckoo singing for longer, symbolically extending summer and delaying the return of winter.

Built during a colder climate

The theory also fits with evidence showing Britain experienced a period of colder conditions when the monuments were built.According to the study, communities living along the coast faced falling temperatures, harsh winters and unusually late springs that would have affected farming and daily life.Nance argues both Holme I and Holme II were constructed as ritual responses to these environmental pressures.He proposes that while each monument may have hosted different ceremonies, they shared the same purpose.“Both monuments are best explained as having different functions and associated rituals, but with a common intent: to end the severely cold weather,” he said.The study also links Holme II with ancient traditions surrounding “sacred kings”, suggesting rituals connected to sacrifice and the restoration of harmony may have taken place there, although this remains an interpretation rather than established fact.

Preserved beneath the marsh

When Seahenge was first built, it did not stand beside the sea as it does today.Researchers believe it originally occupied a salt marsh protected from the coast by sand dunes and mudflats. Layers of peat gradually buried the oak timbers, preserving them for thousands of years by shielding them from oxygen and decay.By the late 1990s, coastal erosion had begun exposing the structure. Archaeologists carried out a full excavation in 1999 before moving the timbers for conservation, fearing the monument would be destroyed if left in place.The decision was not taken well by local residents and campaigners, many of whom believed the monument should have remained where it was found.Partly because of that controversy, the second monument, Holme II was left in the ground. Archaeologists continue to monitor the buried timber circle for signs of erosion rather than excavating it.

The 4,000-year-old excavated remains of Seahenge on display. They were taken away for the purpose of preservation.

A theory likely to spark debate

Independent archaeologists say the study presents an original way of examining prehistoric monuments, although they acknowledge the interpretation will almost certainly generate discussion.Brian Fagan, professor emeritus of archaeology at the University of California, Santa Barbara, who was not involved in the research, said advances in climate science now allow archaeologists to explore links between environmental change and ancient monuments in ways that were impossible until recently.“This is an imaginative look at a complex problem, which brings in interpretations from the intangible as well as climatology,” he said in an email. “It’s an original approach, but it is bound to be controversial.”Stefan Bergh, an archaeologist at the University of Galway who was also not involved in the study, said the paper offered an important framework for understanding Bronze Age beliefs.“We as archaeologists too often shy away from pushing the envelope beyond our comfort zone of hard material evidence,” he told Live Science in an email.“It is, however, often when reaching outside that comfort zone that archaeology really comes alive, which Nance’s paper is an excellent example of.”The study, Ritual responses to climate deterioration at Holme-next-the-Sea: Holme I and II reconsidered, was published in GeoJournal. While the new interpretation does not settle the long-running debate over Seahenge’s purpose, it offers a new possibility that Britain’s mysterious timber circle was built not to honour the dead, but in the hope of bringing warmth back to a landscape gripped by cold.