time and it is the least preserved and least impressive of the five structures. Heritage The ditch offers shelter to wildlife, in what otherwise would be an open and agricultural landscape. It is best accessed from the south at Heydon (OS map reference TL431405). References Fox.C (1923) The archaeology of the Cambridge region: a topographical study of the Bronze, Early Iron, Roman and Anglo-Saxon Ages, with an introductory note on the Neolithic Age. Cambridge: Cambridge University Press History of Cambridgeshire Scheduled monuments in Cambridgeshire Linear earthworks