Mitigation excavation was carried out on land adjoining the Heathfields Estate, near Duxford Airfield, Cambridgeshire. Previous evaluation work had revealed a low background density of flint with a concentration of worked and burnt pieces at the north-west end of the field. This spread appeared to have been cut by a later Neolithic pit filled with highly decorated sherds of pottery derived from six or seven vessels. An unrelated large linear ditch, was located running roughly east-west across the south-western corner of the site. This feature could not be firmly dated. The second phase of excavation revealed that the flint spread and feature were concentrated around a natural feature, probably a solution hollow, which had served as a source of raw lithic material and a focus for the primary reduction of that material from at least the early Neolithic. Similar activity had taken place in the later Neolithic. The spread of pottery around the pit already found suggested either domestic or middening activity around the same natural feature. Parallels were drawn with similar discoveries at nearby sites. The large linear ditch produced some dating evidence. This suggested that the feature was certainly pre-conquest. The probable date was narrowed down to the Roman or Saxon periods, but ambiguity in identification of the pottery types meant a determination could not be made between the two. In the course of investigating the line of the ditch the discovery was made of a large subterranean structure dating to the end of the Second World War or shortly afterwards. The feature was probably an air-raid shelter. The excavation confirmed the importance of the general Duxford Airfield area in a rich archaeological landscape which records several periods.