Report on a programme of archaeological evaluation comprising seven trial trenches excavated on land to the north of Mareham Road, Horncastle, prior to the construction of a residential development. The trenching targeted the ditches of a known Iron Age to Roman rectangular enclosure complex. The presence of the central enclosure was confirmed, but no features corresponding to the proposed western annexe enclosure or extension was encountered. A small assemblage of Late Iron Age pottery was recovered from the fills of the central enclosure.