In order to obtain information about the date of the ancient field systems, excavations were carried out at weekends in the autumn of 1976 at four sites in Nottinghamshire. The ditches at Harworth are crossed by the embankment of a now disused railway, immediately to the north of which a section was dug with minimum interference to the modern farming, in the hope of confirming the interpretation of the feature as a lane. A cutting, 11m x 1m, was excavated across the feature at the edge of the modern field close to the embankment. (1) See E1, E38 and E170 for further cropmark excavations.