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Prehistoric Canals (Dykes) – Wansdyke (4)

Promotional Video – Ancient Prehistoric Canals (Dykes) – Wansdyke Part VI

Extract From Book……………………… Ancient Prehistoric Canals (Dykes) – Wansdyke


The enigmatic Wansdyke, standing prominently in the Wiltshire landscape, has forever captivated the public’s collective imagination.  Its proximity to the famed ancient site of Avebury, with both bearing massive ditches, has led some to surmise a direct connection between them.

Curiously, past and present archaeologists have failed to grasp this apparent link, striving instead to find a simplistic explanation for this enigmatic “linear structure.” Thus, the prevailing belief took root – that it was a bulwark raised to repel the belligerent tides of yore.  Consequently, the term “Saxon” was affixed to these earthworks, as historians of old supposed these “tribes” possessed the martial might needed to accomplish such grand engineering feats to defend their realm.

Yet, in recent decades, this “fact” has faced reexamination, and a novel theory emerged regarding these earthworks as “Boundary Markers” etched upon the landscape.  This alternative proposition, while reassuring, still leaves us grappling with perplexing truths.  Foremost among them is the Dykes’ lack of continuity – both Wansdyke and Offa’s Dyke exhibit sizeable lacunae in their stretches.  Their beginnings and endings emerge with an almost magical quality, unexplained and confounding to the beholder.

Moreover, if indeed these were markers of territorial ownership, then why do certain Dykes, like Offa’s, follow paths that traverse vast separations, such as major rivers?  Surely, a more conspicuous landmark than a mere 4-meter ditch would have served as an apt boundary in such instances.

Alas, the erudite scholars of archaeology have turned a blind eye to the existence of over 1500+ scheduled Dykes scattered throughout Britain and Ireland.  Such a multitude challenges the notion of a uniform purpose, as many of these “boundary markers” also graced uninhabited islands far and wide, enveloping the entire circumference of Britain.

In the spirit of Jacob Bronowski’s method, we must confront these enigmas with a relentless curiosity, unearthing each fragment of evidence and subjecting our suppositions to rigorous scrutiny.  The mysteries of these ancient earthworks shall only yield their secrets to those intrepid minds that dare to question and challenge the established norms of interpretation.  And as history unfolds its layers, we may find ourselves ever closer to unlocking the profound meaning behind these age-old constructs that once shaped the course of human existence upon this storied land.

Robert John Langdon (2023)

Section 4 – HE:1017288 – Section of Wansdyke and associated monuments from east of The Firs to the eastern side of Tan Hill, 3,460 metres (11,533 working days – 20 men, 1.58 years)

HE:1017288 GE
HE:1017288 GE

OS Map

HE:1017288 OS
HE:1017288 OS

1800 Map

HE:1017288 1800
HE:1017288 1800


HE:1017288 Lidar
HE:1017288 Lidar

LiDAR Map (with Mesolithic water levels)

HE:1017288 - With prehistoric water levels
HE:1017288 – With prehistoric water levels

HE schedule suggests that:

The monument, which falls into 12 areas of protection, includes part of Wansdyke running from east of The Firs to the eastern side of Tan Hill,(a kite-shaped enclosure situated on the northern side of Wansdyke on Easton Down), a section of Roman road on Morgan’s Hill, a Neolithic long barrow, five other linear earthwork sections crossed by or abutting the Dyke and 11 Bronze Age bowl barrows adjoining Wansdyke or partially overlain by it.

From the west, Wansdyke runs for roughly 72km ending just outside Marlborough at its east end. The approximately 8.5km long section from east of The Firs to the eastern side of Tan Hill runs across the Downs south west of Avebury and includes the best-preserved continuous length of Wansdyke.

The Dyke includes a substantial earthwork bank which measures up to 30m wide and stands from 1m to 3m high. For the majority of its length the bank lies south and west of a substantial open ditch. This also varies in width but measures up to 36m wide and remains open to a depth of 2m in places.

 The majority of the bank and ditch sections in this area together measure from 30m to 40m across. A further, slighter, bank beyond the ditch to the north is also visible on several sections. The Dyke was built in sections of varying length, with breaks which would have allowed controlled traffic to pass from east to west and for the movement of military patrols beyond the defences. The Dyke is later in date than the Roman road but was already built by the mid-ninth century, when it is mentioned in a Charter.

It is generally believed to be a military frontier work between Wessex and Mercia. It is designed to hold the edge of the high ground on the Downs and to protect the lower lying plains to the south west. The name derives from Woden’s Dyke, after Woden, an important Anglo-Saxon god whose name survives in the word `Wednesday’.

The earlier Roman road includes a 800m long section of the route from Cunetio (Mildenhall) to Verlucio (Sandy Lane). It runs east to west along the north slope of Morgan’s Hill and includes a rare engineered bend at the head of a dry valley after which point the later dyke meets it and runs along its line. The road measures between 8m and 10m wide and its outer (north) edge comprises a well-constructed embankment which stands up to 2m high.

The road is terraced into the slope at this point and the Dyke follows the line of the road for a distance of over 300m. South east of the wireless station on Morgan’s Hill, a 50m long, slightly curved section of linear earthwork runs north from beneath Wansdyke to end in a terminal. It is part of a longer feature, the remainder of which starts about 20m north, runs to the edge of Horsecombe and is the subject of a separate scheduling (SM 21900).

The south end of this feature is not known for certain but it appears to run beneath the Wansdyke for some distance to the east. Immediately south of the Dyke on Roughridge Hill is a Neolithic long barrow. The barrow mound measures about 75m long and up to 32m wide. It stands up to about 1m high. Flanking the mound, but no longer visible at ground level due to the spreading of the mound caused by ploughing, are two quarry ditches which will survive as buried features.

 Although the only example in the scheduling, the barrow is one of a line of more than four Neolithic long barrows which are strung out east to west along the ridge of the Downs, all spaced roughly 1km from their nearest neighbour in either direction.

The enclosure on Easton Down is roughly kite-shaped and has a 6m wide bank which survives up to 0.2m high. Beyond this is a 5m wide ditch which has become infilled due to cultivation but remains visible in places up to 0.5m deep. This ditch has a counterscarp bank 3m wide and up to 0.6m high in the north west corner. Although the western end has been levelled by cultivation, it is known from aerial photographs and partial excavation to survive as a buried feature. Previous records also show that the inner bank originally stood 1.5m or more in height while the counterscarp bank stood 1m high.

The excavations showed that the southern boundary of the enclosure lies below the line of the later Wansdyke, which appears to change course slightly at this point. The excavations also produced Romano-British pottery sherds from the interior of the monument, indicating that it was a settlement during that period.

The section of Wansdyke on Tan Hill crosses a series of four earlier linear boundary ditches which form part of an earlier prehistoric land division. Three of these run from north to south and the last runs east to west and is abutted by at least one of the others. These boundaries survive as buried features clearly visible on aerial photographs and, despite being levelled in places, remain visible at several points above ground. The ditches vary in width from 3m to 8m across and several have adjacent banks about 0.75m wide and up to 0.3m high.

Together they form three sides of a rectilinear field within which is located a small Bronze Age barrow cemetery containing five bowl barrows. Two of these are partially overlain by the Wansdyke. The barrow mounds measure from 12m to 20m in diameter and stand between 0.2m and 1m high.

All but one of these are surrounded by quarry ditches which vary from 1m to 2m in width and survive buried below the present ground level. There are six further bowl barrows along the length of Wansdyke from east of The Firs to the eastern side of Tan Hill which are partially overlain by the Dyke. Some of these are outliers of groups of barrows or cemeteries, the remainder of which, where appropriate, are the subject of separate scheduling’s. These barrows vary from 10m to 20m in diameter and stand up to 3m high. Their surrounding quarry ditches measure from between 1m to 2m wide.

Several barrows near to Old Shepherds’ Shore were partially excavated in the 1850s and finds included burnt animal and human bone and fragments of Bronze Age pottery.

Fig.61 resolves most of the conjecture on what Dykes are for and why they were constructed.  The Dyke now splits north and south – but why?

If it was a boundary marker, what is it marking out? If it is defensive, why stop just a few metres heading BOTH ways – what are you defending??

The LiDAR and satellite (during a dry spell) pictures show the paleochannels (ancient water channels that are usually unseen in the ground are very visible. Remarkably, we see that the ditches of Wansdyke meet up with these channels and show that Wansdyke had a junction where boats could leave and join.

The deep cuts to the south (not considered part of Wansdyke are ancient and currently used as footpaths.  Moreover, another large ditch (not on the Historic England schedule) disappears into the old Paleochannel river (Fig. 34)

Moreover, this ditch enters not only a watery Paleochannel but also a source of massive Sarsens Stones (Fig.65). The old OS maps show that once these stones were abundant in the local Paleochannels from the last Ice Age – the easiest way to transport them would be by boat via Wansdyke?

The tiny Dyke coming out of Wansdyke is quite mysterious as it does seem to have any practical purpose.  It could be a parking feature for the Dyke if boats needed to stop for some reason (site nearby), or it could be used as a water regulator as seen on Canals today called a ‘Cross Head Regulator’ as springs may have needed to be reduced to slow the flow of the Dykes Flow?

Another ditch feature that joins Wansdyke at Tanhill.

We see a very complex series of ditches that join Wansdyke and go down into the Dry River Valley.  This looks like a significant terminal for Wansdyke and a possible trading site with Ditches allowing boats to moor.

Moreover, historically (Aubrey recorded that in the 17th century, the fair was held “within an old camp”), this has been a trading side since Medieval times and had its white horse.

Pic 68. It shows the extent of the ditch works at Tanhill Fair; it goes much further in both directions than the Historic Monument scheduled monument register suggests, and it connects in two places to Wansdyke and a further cut to the top of the old Tanhill Fair site.

Again, this shows that Wansdyke was not defensive or a marker in the landscape as this feature (which connects to the main Dyke) is not recognised as part of Wansdyke but clearly is contemporary and can only be for the transportation of boats via a canal.

Morgan Hill Kink


To the East of Morgan Hill is found a bizarre Kink in Wansdyke. This is best seen on an OS map showing not only this strange direction but also the obstacles it avoided.

From the topology of the hill – there is no reason to ‘Kink’ to the right, then take a tight 90-degree turn to the left – then left again (rather than continuing), then right turn to get back in line again.

This discounts the fortification idea as it goes downhill, making it lower from its height advantage, and then it takes two turnings (and a hell of more work) to get back online – almost 100% more time and effort.  This obviously excludes it as a marker for the same construction time and resource reasons.

Moreover, again it does help us date this feature as Round barrows surround this kink on both sides. So, are we saying that the builders (if it was younger than the Bronze Age) went around the Barrows rather than over them?

Or is it now clear that the Barrows we created at a later date match the contours of the Dyke?

Branch off Wansdyke

Missing from all OS maps at the top of Morgan Hill is a branch going North and down to the Mesolithic Rivers of prehistory.  This feature is captured by Historic England: Cross ridge dyke on Morgan’s Hill –

The monument includes a 560m long section of a cross ridge dyke situated on Morgan’s Hill. The dyke runs from NNW to SSE across the east-west aligned ridge, dividing Morgan’s Hill into two parts. The dyke has a bank c.8m wide and up to 1.5m high. To the East of the bank lies an 8m wide ditch which provided material for its construction and enhanced the effectiveness of the boundary.

This has been partly infilled by cultivation but is open to a depth of 0.3m in places, and is visible on aerial photographs. The bank and ditch are interrupted by a number of openings through which animals and people could pass. It is not clear how many of these are original.


 A further section of the dyke, situated to the south is crossed by the Wansdyke which is later in date. This further section is the subject of a separate scheduling. Excluded from the scheduling are the post and wire fences which cross it and run along its length, although the ground beneath is included.

Both have a bank and ditch and meet on top of Morgan’s Hill – they are one of the same but probably made on a different date.  Interestingly, a paleochannel cuts through the Dyke, and that part is missing showing that this section of the Dyke is ancient (Early Mesolithic?)

East Wansdyke was built across chalk, yet excavations suggest that the builders kept the turf taken during the digging of the ditch to one side and used it to cover the bank; this stabilised the bank but also meant that it did not stand out as a white line across the green downland (Green 1971 87  32-33) and yet more reasons for this not to be either a boundary marker or defensive ditch.

If we look north from Morgan’s Hill (Fig. 77), we can see in the landscape features from LiDAR that Wansdyke turned north and followed the Roman Road and was met by another ditch from the central Wansdyke canal. This is confirmed by the presence of Round Barrows to the right and by the raised river shorelines (top of picture), which the Roman used as an existing platform bank for their road so time later.


Chronology (Smoking Gun)

A piece of evidence that has been ignored about Wansdyke and its dating is the Roman road that heads East over Morgan’s Hill and then veers North – built on the Ditch of Wansdyke and then cutting through the bank as shown on Page 66 – Fig.40.

Archaeologists have always questioned the accuracy of this drawing and suggest an exaggeration was drawn rather than an accurate representation.

This can now be finally ‘put to bed’ through LiDAR, which shows the same cut through the bank bending towards the Roman deviation indicating that this road was built AFTER Wansdyke was constructed – the smoking gun of prehistoric dating of Dykes.

Figure 78 - Roman Road cuts through Wansdyke making it older!
Figure 78 – Roman Road cuts through Wansdyke making it older!


3D Book Template wansdyke edited 1
Blank bookcover with clipping path

This was an extracts from the NEW Book Ancient Prehistoric Canals (Dykes) – Wansdyke available on Amazon as a FULL COLOUR HARD BACK (£19.95) or a ECONOMY (£4.99) SOFTBACK black and white VERSION – it is also available as a KINDLE (£1.99) book. For further information about our work on Prehistoric Britain visit our WEBSITE or VIDEO CHANNEL.

Product details

  • ASIN ‏ : ‎ B0BF31GQKC
  • Publisher ‏ : ‎ Independently published (18 Sept. 2022)
  • Language ‏ : ‎ English
  • Hardcover ‏ : ‎ 134 pages
  • ISBN-13 ‏ : ‎ 979-8353488897
  • Dimensions ‏ : ‎ 15.24 x 1.3 x 22.86 cm
  • Illustrations: 85
  • Customer reviews: 5.0 out of 5 stars    1 rating

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Ancient prehistoric canals dykes that dont make sense?