Fleam Dyke

The dyke is a seven-metre-high linear bank and ditch which ran from Fulbourn to Balsham. Most of it survives and is now a footpath. In the nineteenth and early twentieth centuries Anglo-Saxon weapons and burials were found, and the dyke was thought to have been built in the seventh century as a defence of the Kingdom of East Anglia in its wars with Mercia.

An excavation in 1991 established that it had been built in several phases, the first between 330 and 510, and the last between 450 and 620. It is now believed most likely to have been built by early Anglo-Saxon settlers in the fifth century as a defence against Romano-British attempts to recover their territory.

At Mutlow Hill the dyke runs through a Bronze Age barrow, which was reused in the Roman period as a temple.[4]

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.

Icknield Way was of huge historical importance. 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. To that extent, Fleam Dyke, Flendish Hundred and Fulbourn have their place in history.

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.[5][6] 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.[7]

The Harcamlow Way long distance footpath runs through the site.

• Illustrated map of Fleam Dyke