The Walton Basin – the Welsh Answer to Salisbury Plain
The 50 to 60 LHS members and visitors who attended the Society meeting on Wednesday 20 January were impressed and informed with the talk given by Nigel Jones on the ancient monuments in the Walton Basin. Nigel Jones is a principal archaeologist of the Clwyd & Powys Archaeological Trust and has spent 5 – 6 years researching the Basin’s archaeology.
The Walton Basin is about 6 x 5 km in size, of relatively low-relief farmland and surrounded by hills. It lies some 5 km WSW of Presteigne. It was an ancient, and is now a present route into Wales through New Radnor on the W flank of the Basin.
A number of tumuli and evidence of Roman remains have been identified across the Basin but its major significance, in terms of Neolithic monuments, was not recognised until the 1990s. The reason for this appears to be that the basin was part of a glacial lake towards the end of the last Ice Age [approx.12000 years ago] and the surface deposits are predominantly fine gravels over much of the area but with some clay to the east, resulting in a spring line. Consequently, due to the lack of any building stone, there is only one Bronze Age stone circle [Fourstones] in place; earlier structures had to be built of wood so no obvious surface traces remain.
In the 1990s a careful examination of aerial photographs revealed, through crop marks, the presence of some amazing sub-surface structures. Some of these were examined in the late 1990s by Helmut Becker using geophysics [magnetometry]. Now such geophysical methods are in relatively common use in archaeological studies but not so in the 1990s. However geophysics can only go so far and archaeological excavations were needed.
Nigel Jones described the findings of various studies, starting with those related to the oldest structures. He noted that there were many finds of Neolithic flint tools across the Basin; generally found in the arable fields. The first monument he described was a Mesolithic causeway enclosure radio-carbon dated at 3700 -3300BC. The aerial photography, geophysics and excavations showed a structure about 280m long x 180m wide. It is surrounded by double ditches 2m deep x 3m wide. Four other causeway structures have been identified in Wales and others are suspected but not yet confirmed. These monuments were initially considered to be defence structures, but this is now rejected. There is speculation that they may have been for community gatherings or trading.
The next Neolithic structure described was a 4.6km long cursus. This straight ditch – the Hindwell Cursus – running NE-SW is slightly shorter than that adjacent to Stonehenge in Wiltshire but is still one of the longest in Britain. There is also evidence of a shorter cursus near Walton Green. The cursus ditches date from between 3950-2470BC. Their use is uncertain.
Neil Jones then described 3 palisaded structures. These were made from massive individual timbers placed relatively closely and upended into preformed ditches or post-holes up to 2m deep. The ends of the timbers are charred probably to resist rot. The construction is dated 2900-2500BC. The largest of these palisaded enclosures adjacent to Hindwell farm is truly massive with a diameter of about 500m. Fifteen palisaded enclosures have been found in Britain – but this is the largest to date. It is estimated that 1100 oak trees were needed to build it and the trees may have been put into the ditches/holes with their roots uppermost. The palisade appears to have been destroyed by fire at an unknown date.
The scale of the structure is such that it must have been built as a communal effort. This implies that there was an agricultural surplus giving time for activities other than survival. Very little is known about the people who lived in the area and no settlements have been found.
In the Bronze Age there are numerous burial mounds and the Fourstones circle is from this period. There are also several Iron Age sites.
During Roman times there was much activity in the Basin with a well- established camp at Hindwell and three marching camps near Walton.
Nigel Jones noted that funding for the archaeological work has now come to an end but in view of the importance, particularly of the large Neolithic monuments, increased awareness of these finds is needed locally and nationally.
The many questions to Nigel at the end of the meeting showed how this excellent presentation captured the imagination of the audience; more is known that many us realised, and intriguingly so much remains unknown, perhaps to be revealed by further digs in the area
A booklet produced by about the Walton Valley with much detail found in the talk is available on-line, available to be downloaded at http://www.cpat.org.uk/resource/booklets/walton.pdf