Prehistoric Cornwall Canals (Dykes)

GE Map of Prehistoric Cornwall Canals (Dykes)

Old Map

Geological Landscape

Landscape/Terrain

Database of DYKES (Linear Earthworks) in Cornwall

(Click the ‘HE Entry Ref: Number’ (if blue) for more details and Maps)


Name	HE Entry Ref:	NGF	Length (m)	Overall Width (m)	Ditch Width (m)	Bank Width (m)
Earthwork 100yds (90m) ESE of Tregidden	1004335	SW 75573 22941
Part of a medieval boundary dyke 220m east of Golitha House	1004364	SX 22671 68380
Linear boundary called the Giant's Hedge	1006681	SX 17149 57451
Linear earthworks, probably 17th century, W of Godrevy	1007284	SW 58253 43029
Stannon Stone Circle, prehistoric field system, hut circle settlement, cairns, cist, linear boundaries and medieval building north of Dinnever Hill	1007764	SX 12685 79833
Prehistoric embanked platform cairn and linear boundary with superimposed medieval boundary and adjacent clearance cairn on Dinnever Hill	1007768	SX 12135 79284
Prehistoric linear boundary, adjacent irregular aggregate field system and hut circles, incorporated cairns and medieval grave on north-west Roughtor	1008187	SX 14474 81056
Prehistoric coaxial field system, incorporated and adjacent hut circles, stone setting, linear boundaries and medieval settlement on Fox Tor and Treburland Farm	1008245	SX 22958 78720
Prehistoric linear boundary and adjacent round cairn 938m north-west of Wardbrook Farm	1008845	SX 24958 73842
Prehistoric linear boundary with adjacent stone hut circle, two round cairns and cairnfield 1.125km north of Wardbrook Farm	1008897	SX 25278 74283
Unenclosed hut circle settlement and adjacent Prehistoric linear boundary 800m SSE of Trewortha Farm	1008958	SX 24747 74384
Prehistoric linear boundaries, cairn and enclosure 1.225km north-west of Wardbrook Farm	1008982	SX 24751 74149
Unenclosed hut circle settlement with adjacent enclosure and linear boundary 1.41km SW of East Castick Farm	1009805	SX 25492 75416
Three adjoining Prehistoric linear boundaries on Bearah Tor, 687m SW of Nodmans Bowda Farm	1010220	SX 26390 74637
Neolithic long cairn, Prehistoric regular and irregular aggregate field systems, linear boundaries and medieval enclosure 625m W of Blackcoombe Farm	1010221	SX 26296 73871
Prehistoric and medieval linear boundary 1.34km south of Eastmoorgate	1011386	SX 22081 77603
Prehistoric embanked avenue with incorporated funerary cist 210m WNW of Showery Tor	1011501	SX 14728 81380
Prehistoric and medieval linear boundary with associated peat stack platform 475m SSW of Eastmoorgate	1011509	SX 22059 78374
Prehistoric linear boundary and adjacent subsidiary boundary 1km west of Tresellern Farm	1011874	SX 22645 76808
Linear bowl barrow group on Ligger Point, 250m west of Penhale Mine	1016990	SW 75927 58032
Prehistoric linear boundary and field system, medieval enclosure and tin miners' caches 1.06km north-west of Wardbrook Farm	1015975	SX 24678 73939
Prehistoric linear boundary on Dropnose Point, Gugh	1008324	SV 89322 08103
Three platform cairns and adjacent prehistoric linear boundary on Wingletang Down, 70m west of Crooked Rock	1009276	SV 88521 07686
Prehistoric linear boundary 50m ENE of Mount Todden Battery, St Mary's	1010165	SV 93042 11575
Prehistoric linear boundary on Puffin Island	1010175	SV 88154 13429
Prehistoric linear boundary south east of Horse Rock on Porth Hellick Down, St Mary's	1013668	SV 92992 10793
Prehistoric field system and kerbed cairn, with post-medieval kelp pit and linear boundary on southern White Island	1014789	SV 92508 17341
Prehistoric linear boundary SSE of The Island, Bryher	1014991	SV 88128 14815
Prehistoric linear boundary and Civil War fieldworks on north western Toll's Hill, St Mary's	1015662	SV 92664 12154
Prehistoric linear boundaries, house platform and cairn on south western Peninnis Head, St Mary's	1015669	SV 90974 09526
Prehistoric linear boundary and cairns south west of The Bar, Bryher	1016170	SV 88144 15093

Dykes Ditches and Earthworks

Indeed, the modern term “dyke” or “dijk” can be traced back to its Dutch origins. As early as the 12th century, the construction of Dykes in the Netherlands was a well-established practice. One remarkable example of their ingenuity is the Westfriese Omringdijk, stretching an impressive 126 kilometres (78 miles), completed by 1250. This Dyke was formed by connecting existing older ‘dykes’, showcasing the Dutch mastery in managing their aquatic landscape.

The Roman chronicler Tacitus even provides an intriguing historical account of the Batavi, a rebellious people who employed a unique defence strategy during the year AD 70. They punctured the Dykes daringly, deliberately flooding their land to thwart their enemies and secure their retreat. This historical incident highlights the vital role Dykes played in the region’s warfare and water management.

Originally, the word “dijk” encompassed both the trench and the bank, signifying a comprehensive understanding of the Dyke’s dual nature – as both a protective barrier and a channel for water control. This multifaceted concept reflects the profound connection between the Dutch people and their battle against the ever-shifting waters that sought to reclaim their land.

The term “dyke” evolved as time passed, and its usage spread beyond the Dutch borders. Today, it represents not only a symbol of the Netherlands’ engineering prowess but also a universal symbol of human determination in the face of the relentless forces of nature. The legacy of these ancient Dykes lives on, a testament to the resilience and innovation of those who shaped the landscape to withstand the unyielding currents of time.

Upon studying archaeology, whether at university or examining detailed ordinance survey maps, one cannot help but encounter peculiar earthworks scattered across the British hillsides. Astonishingly, these enigmatic features often lack a rational explanation for their presence and purpose. Strangely enough, these features are frequently disregarded in academic circles, brushed aside, or provided with flimsy excuses for their existence. The truth is, these earthworks defy comprehension unless we consider overlooked factors at play.

One curious observation revolves around the term “Dyke,” inherently linked to water. It seems rather peculiar to apply such a word to an earthwork atop a hill unless an ancestral history has imparted its actual function through the ages. Let us consider the celebrated “Offa’s Dyke,” renowned for its massive linear structure, meandering along some of the present boundaries between England and Wales. This impressive feat stands as a testament to the past, seemingly demarcating the realms of the Anglian kingdom of Mercia and the Welsh kingdom of Powys during the 8th century.

However, delving further into the evidence and historical accounts challenges this seemingly straightforward explanation. Roman historian Eutropius, in his work “Historiae Romanae Breviarium”, penned around 369 AD, mentions a grand undertaking by Septimius Severus, the Roman Emperor, from 193 AD to 211 AD. In his pursuit of fortifying the conquered British provinces, Severus constructed a formidable wall stretching 133 miles from coast to coast.

Yet, intriguingly, none of the known Roman defences match this precise length. Hadrian’s Wall, renowned for its defensive prowess, spans a mere 70 miles. Could Eutropius have referred to Offa’s Dyke, which bears remarkable similarity to the Roman practice of initially erecting banks and ditches for defence?

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