13th January 2001

Seahenge Assessment
by Brian Ayers and Andy Hutcheson
of Norfolk Museums & Archaeology Service

Edwin made a description of the exposed remains, a scaled sketch of the various elements, took photos and located the monument on a map.  He reported the find to English Heritage.
Its importance was soon recognised by EH which made funds available to Norfolk Archaeological Unit for an assessment and preliminary investigation.
Work in late 1998 identified Seahenge was at risk from the sea, threatened by dehydration, wood-boring molluscs, salts attacking the wood and wave action.   An accurate record was made of the monument, locating it using satellite geographical positioning technology and a small trench was dug to assess the depth of the timbers.
How old was it?
The combined use by English Heritage of radiocarbon dating, dendrochronological (or tree-ring) analysis and a 150 year old statistical technique invented by English mathematician Thomas Bayes succeeded - with amazing accuracy - in dating the felling of the upturned oak to early summer 2050BC and its surrounding posts to spring or early summer of the following year, 1049BC.
This discrepancy between the two dates could suggest the oak was positioned before the circle was built.
This sequencing of events, resulting in the gradual construction of a ritual monument, was common in the early Bronze Age.
The techniques used for dating were innovatory and of international importance.
The results were so startling they were published by Nature, the international science journal.
Was Seahenge by the sea?
The assessment also showed that Seahenge was built on dry land or, rather, or land which was low-lying and perhaps marshy.
It is not generally recognised that the beach area at Holme, now engulfed by the sea, was some distance from the coast in the Bronze Age.
The timbers had been preserved by freshwater peat which subsequently was covered by marine sands.
Further coastal change is now stripping away the sands, destroying the peat and uncovering timbers.
Was Seahenge a henge?
Henges were built in the Late Neolithic period (they were largely out of date by the Bronze Age) and are massive enclosed areas such as can be seen at Stonehenge, Avebury and Durrington Walls (all in Wiltshire).
Large scale monuments of this period are rare in Norfolk, although there was a henge constructed of wood at Arminghall just to the south of Norwich (it was discovered by air photography in the 1920s).
Seahenge is a misnomer as it is not a henge but a smaller, different kind of monument.
Why was it decided to excavate the circle?
Assessment work demonstrated that Seahenge was an exceptional monument constructed at the beginning of the Bronze Age when metal tools were being used for the first time.
Those parts of the timber which were still buried were well-preserved but the tops were very badly eroded and this erosion was continuing.
Studies of the beach over many years have shown that it is one of the fastest-changing beaches in Norfolk and that there was a real danger Seahenge would be destroyed before it could be studied and the information preserved for future generations.
It was therefore decided to excavate the site before it was destroyed further by the sea.

A section of the honeysuckle rope

How was it built?
The dating evidence showed that Seahenge was built over two summer seasons.
A pit was dug in 2050BC, into which an inverted oak-tree bole was lowered.   Holes had been pierced through the tree in order to thread a honeysuckle rope which was used to help position the timber in the hole.
The roots of the tree were then left pointing into the air until the following year.
In 2049PC, oak logs were felled and split lengthways.  Splitting seems to have been done on site because wood chips were found during the excavation.
A trench was dug and the posts were set vertically within it, the bark side facing outwards and the cut face inwards.  The effect would have been to present a faceted face to the interior and an artificial tree to the exterior.

A very narrow entrance was left, perhaps to aid construction.   It was subsequently blocked with a pair of small posts. Detailed dating still needs to be undertaken on the blocking in order to see if the entrance was blocked at the time of construction or later. Timbers in water at Flag Fen showing the 'gate' post

How high was Seahenge?
The posts did not extend more than a metre into the subsoil.  It is unlikely therefore that the structure was higher than three metres when first built.
How were the timbers cut?
Toolmarks survive on the faces of many of the timbers.  These indicate the posts were trimmed using a Bronze-Age axe known as a palstave.

Was Seahenge easy to build?
No.  The builders actually made it difficult for themselves, twice choosing to cut down oak trees with relatively primitive technology during the summer season, which means the trees would have been in leaf and bursting with sap.  It must have meant much hard work.
Why was Seahenge built?
This will always be a difficult question to answer but it was clearly intended as a ritual monument.  It is best to consider the implications of constructing it in summer.
The great central oak tree, so difficult to cut down, was trimmed of branches and then inverted.  Many societies believed - and still believe - in three areas of life:   above, on and under the earth.
Was the oak tree, a potent symbol of life on earth, being offered to those that live under the earth?  Were its roots offering life up to the skies?
The protective wall around the tree is also of interest.
In common with other Bronze-Age monuments, it may have been constructed with regard to astronomical observation.
Archaeologists plotted the recorded positions of the timbers and the possibility exists that the entrance to the circle was in alignment with the midwinter sunset.   Work continues on this study.
Seahenge was thus probably a monument, perhaps linking life on earth with the sky or the spirit world.
Other discoveries
This stretch of coast has a long history of intriguing and rare archaeological discoveries.
At Titchwell, a few kilometres east of Holme, a nationally important flint scatter site dating from the end of the last glacial period was discovered in the 1980's.
Between Titchwell-Brancaster and Hunstanton are the remains of a prehistoric submerged forest.  In the 19th century, a 4500 year old stone axe was discovered, reputedly embedded in a tree stump in this forest.
In addition to Seahenge, part of another timber-post circle has been discovered on the beach just over 100m to the east. See New Mysteries
It is clearly different from Seahenge with, at its centre, a probable wicker lined pit with two logs lying on the surface.
Both logs are located within the circumference of the pit and are slightly concave in appearance.
It has been suggested that a post further out on the beach may be part of another circle.  This post is very badly decayed and all peat around it has gone together with any other timbers.  The post may date from Bronze Age but it could also be much more recent.
Ceremonial landscapes
It is possible that some features in the Holme area represent eroded barrows or burial mounds.  Barrows can be seen throughout Britain and the Continent and round ones, like these, date mainly from the Bronze Age.
There are several dozen well-preserved barrows in Norfolk.  There were many more now only visible as circular cropmarks which have been destroyed through millennia of farming.
The chalk downlands of Wiltshire, Dorset, Hampshire and the wolds of Lincolnshire have the greatest concentration of surviving mounds, the national total being tens of thousands.
These are the cemeteries of the period and would have been the focus of religion and worship.
Excavation of many barrows across Britain and Europe means that their archaeological sequences are well understood.  Mounds, it has been discovered, were the final event in the life of the monument.
Prior to this the ritual site often consisted of stake or post circles surrounding a central burial.
Sometimes, other burials were placed in and around the circle. Rituals were enacted including feasting. Cooking sometimes took place on site, leaving bones and burnt stones as evidence.
The partial circle at Holme may represent such a site.
The sea has denuded the landscape, eroded any mounds and stripped any deposits but another barrow cemetery in the area is known.  This is located about two kilometres to the south and consists of four monuments now only visible as cropmarks in a ploughed field.
What happens to Seahenge now?
The results of the excavation continue to be analysed by specialists across Britain.
The work includes examination of environmental data from he site as well as the timbers themselves.
A survey report on the timbers elsewhere on the beach has been prepared and will be published in the next few weeks.
Academic publication in archaeology is a painstaking process.  Much more remains to be discovered about Seahenge from analysis of the data.
It is hoped to publish a popular pamphlet soon.
The timbers are being cared for at Flag Fen near Peterborough which is open to the public.  It has been decided locally that they should be returned to Holme and reburied.  (see Timber Circle Forum - Meeting at Holme)
This would be done in such a way that the deep deposits would preserve the timbers for future generations.
Monitoring would take place after reburial to ensure the timbers remain stable (this can be done with wire and would not involve further excavation).
What is happening at Holme now?
The Holme area is being monitored by the Norfolk Museums & Archaeology Service with the help of the Norfolk Wildlife Trust and local volunteers, including John Lorimer who made the original discovery.  There are no plans for further excavation at Holme.
Archaeologists welcome information from local people of discoveries and record them on the county Sites & Monuments Record.