|Site of Special Scientific Interest|
|Grid reference||TL 551 539 |
|Area||7.8 hectares |
|Location map||Magic Map|
Fleam Dyke is a linear earthwork between Fulbourn and Balsham in Cambridgeshire, initiated at some timepoint between AD 330 and AD 510. It is three miles long and seven metres high from ditch to bank, and its ditch faces westwards, implying invading Saxons as its architects. Later, it formed a boundary of the Anglo-Saxon administrative division of Flendish Hundred. At a prominent point, the earthwork runs beside Mutlow Hill, crowned by a 4000-year-old Bronze Age burial mound.
The dyke is located near Cambridge, between Fulbourn and Balsham. It forms a barrier across an open chalkland ridge, bounded near Fulbourn by marshy fenland and near Balsham by 90-metre-high formerly wooded hills ("The Ambush"). It is three miles long and seven metres high from ditch to bank, and its ditch faces southwest. Most of the earthwork survives and a footpath leads along the crest of the bank (now part of the modern Harcamlow Way long distance footpath).  Possible extensions to Fleam Dyke occur at both the south and north ends, and a further part of it might exist three miles to the northwest, from Quy Fen to the River Cam at Fen Ditton.  
At Mutlow Hill the dyke runs beside a pre-existing Bronze Age barrow dated to 2000 BC, which contained eight urns with cremated human remains, and which was reused in the Roman period as a shrine. The finding of a fourth-century Roman coin under the dyke established the dyke's post-Roman construction date. In the nineteenth and early twentieth centuries Anglo-Saxon weapons and burials were found. An excavation in 1991, on occasion of widening the A11 road, established by radiocarbon dating that it had been built in several phases, the first between AD 330 and 510, and the last between AD 450 and 620. It is believed most likely to have been built by early Anglo-Saxon settlers in the fifth century AD as a defence against Romano-British attempts to recover their territory. 
In later Anglo-Saxon times, the northern part of Fleam Dyke was also the boundary between Flendish and Staine Hundreds (county subdivisions).  In this period, when villages grew and parish boundaries were established, parishes in this part of the county were long and narrow stretching from the fens to the Icknield Way (now the A11) as this gave access to wood from the uplands, thatching from the fens and fertile local soil. Thus, what is now Stow-cum-Quy (with its potentially separate section of Fleam Dyke) was originally the northern part of the two Wilbraham villages (Great Wilbraham and Little Wilbraham) situated near the main Fleam Dyke.  The main part of Fleam Dyke today still constitutes a parish boundary.
Fleam Dyke is one of four substantial earthworks, each a high bank with a ditch on its southwest side, running across the chalk downland ridge that carries the Icknield Way (and the Roman Road) across south Cambridgeshire. The others are Devil's Dyke, Brent Ditch and Bran Ditch. In Suffolk, to the north west of Bury St Edmunds, a fifth earthwork, Black Ditches, guards the Icknield Way. Malim (1997) notes that Fleam Dyke experienced at least three phases of construction and thus had the most complex history of the earthworks, and suggests this could be "because it was built, taken, then retaken and refortified a number of times during the fluctuating fortunes of war during the Dark Ages." 
Icknield Way runs from the Berkshire Downs to East Anglia and was historically important. It is certainly a pre-Roman path often claimed as the oldest in England and was later named one of the "Four Highways" of medieval England on which travellers had royal protection.
Fleam Dyke is one of 286 sites selected by Charles Rothschild in 1912 to 1915 as wildlife sites "worthy of preservation" in Britain and Ireland.   The steep banks of the earthwork have species-rich chalk grassland, a rare habitat in the county. The dyke, which is maintained by grass cutting, is the only Cambridgeshire site for the common juniper.  The entire length is now a Scheduled Monument  and a 7.8-hectare (19-acre) biological Site of Special Scientific Interest.  
Wansdyke is a series of early medieval defensive linear earthworks in the West Country of England, consisting of a ditch and a running embankment from the ditch spoil, with the ditching facing north.
Fulbourn is a village in Cambridgeshire, England, with evidence of settlement dating back to Neolithic times. The village was probably established under its current name by 1200. The waterfowl-frequented stream after which it was named lies in the east, close to the division between arable and fenland.
Great Wilbraham is a small village situated in a rural area some seven miles (11 km) to the east of Cambridge, between the edge of an area of low-lying drained fens to the west and north, and higher ground beyond the A11 to the east.
Devil's Dyke or Devil's Ditch is a linear earthen barrier, thought to be of Anglo-Saxon origin, in eastern Cambridgeshire and Suffolk. It runs for 7 miles in an almost straight line from Reach to Woodditton, with a 10-metre-high ditch and bank system facing southwestwards, blocking the open chalkland between the marshy fens to the north and the formerly wooded hills to the south. It is a Scheduled Monument, a biological Site of Special Scientific Interest and a Special Area of Conservation.
Grim's Ditch, Grim's Dyke or Grim's Bank is a name shared by a number of prehistoric bank and ditch linear earthworks across England. They are of different dates and may have had different functions.
Horningsea is a small village north of Cambridge in Cambridgeshire in England. The parish covers an area of 2.6 square miles. It lies on the east bank of the River Cam, and on the road from Cambridge to Clayhithe. The nearest railway station is Waterbeach, 1+1⁄2 miles (2.4 km) away.
Fen Ditton is a village on the northeast edge of Cambridge in Cambridgeshire, England. The parish covers an area of 5.99 square kilometres (2 sq mi).
Stow cum Quy, commonly referred to as Quy, is a village and civil parish in Cambridgeshire, England. Situated around 4 miles (6.4 km) north east of Cambridge lying between the Burwell Road (B1102) and the medieval Cambridge to Newmarket road, it covers an area of 764 hectares.
Newmarket is a former United Kingdom Parliamentary constituency. It was created upon the splitting up of the three member Cambridgeshire constituency into three single member divisions in 1885. The seat was abolished in 1918.
Fulbourn Fen is a 27.3-hectare (67-acre) biological Site of Special Scientific Interest east of Fulbourn, Cambridgeshire. It is privately owned and managed by the Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire.
Bran Ditch or Heydon Ditch is generally assumed to be an Anglo-Saxon earthwork in southern Cambridgeshire, England.
Brent Ditch is generally assumed to be an Anglo-Saxon earthwork in Southern Cambridgeshire, England, built around the 6th and 7th Centuries. However most of its structure has been lost over time. The site is scheduled as an ancient monument by Historic England.
Black Ditches is an earthwork close to the village of Cavenham of Suffolk, and part of it is a biological Site of Special Scientific Interest (SSSI). The earthwork is 4.5 miles long between the River Lark at Lackford and the Icknield Way. It is described by the Suffolk Historic Environment Record as having no direct dating evidence but "by analogy with other linear earthworks in the region it is usually assumed to be post Roman".
Wandlebury Hill Fort, also known as the Wandlebury Ring, is an Iron Age hillfort located on Wandlebury Hill in the Gog Magog Hills, Cambridgeshire, England, to the southeast of Cambridge. Now a country park, it was the most important of three hillforts in the downs.
The Roman Road in Cambridgeshire, also known as Worsted Street Roman Road, is a 12.4-hectare (31-acre) linear biological Site of Special Scientific Interest stretching from south-east of Cambridge to north of Linton. It is also a Scheduled Monument, and is maintained by Cambridgeshire County Council.
Flendish Hundred was a pre-Norman administrative division of the county of Cambridgeshire, England. It probably got its name from Fleam Dyke. Hundreds were intermediate administrative divisions, larger than villages and smaller than shires, that survived until the 19th century. It was probably created in the early 10th century. Flendish was first recorded in the Domesday Book. In the 11th century Flendish hundred contained four vills, later divided into five parishes: Fulbourn, Teversham, Hinton, and Horningsea.
Zouches Manor was an Anglo-Saxon moated manor in Fulbourn Fen, a Site of Special Scientific Interest in the village of Fulbourn, Cambridgeshire, England. It is one of the historic Five Manors of Fulbourn and recorded to have existed 1066 AD to 1539 AD.
The Harcamlow Way is a waymarked walking route in England running in a figure-of-eight from Harlow to Cambridge and back again, hence its portmanteau name. On the way it runs through Essex, Hertfordshire and Cambridgeshire. The route is 141 miles long.
Coordinates: 52°09′36″N0°15′58″E / 52.16°N 0.266°E