it was a complex of separate sections. English Heritage's monument scheduling suggests that Grim's Ditch may be of Bronze Age or Early Iron Age date. Another can be found in west Hampshire, midway between the villages of Upton and Netherton. Hertfordshire The route of the Grim's Ditch in Hertfordshire passes through the town of Berkhamsted, and remnants of the earthwork can be seen on Berkhamsted Common. The Historic Environment Record for Hertfordshire suggests that the section on Berkhamsted Common is of Iron Age or early Roman date for the monument is most likely than the Bronze Age (date suggested for the rest of Grim's Ditch because it is larger here and does not follow the contours of the landscape like the rest of Grim's Ditch. Oxfordshire There are three linear earthworks in Oxfordshire that are called Grim's Ditch. The south Oxfordshire Grim's Ditch, also known as the Mongewell Ditch is a section between Mongewell on the banks of the Thames near Wallingford, and Hayden Farm near Nettlebed in the Chilterns escarpment. Part of the western end was excavated during the building of Winterbrook Bridge, and dated as late Iron Age/early Roman. The ditch has a bank on the north side which suggests that its function was to bar passage into the southernmost part of Oxfordshire. Considering the location of the ditch across the Chiltern Clayland, it is possible that the ditch could have functioned to block movement into Oxfordshire up the Thames valley. The heavier soils behind the ditch are far easier to move over, creating a solid defensive position. However, since a neighbouring set of earthworks, Streatly Ditches, faces north, it would be difficult to come to the conclusion that the two create a barrier against movement up the Thames valley. Furthermore, it could be argued that there is a possibility that people could simply cross the river at Streatley and just avoid both dykes altogether. In terms of dating, one of the few finds on the site is a coin, dateable to the beginning of the 1st century BC. The ditch can also be compared to the identically-arranged Chichester Entrenchments, dating the ditch to around the Iron Age. The soil composition shows light soils being cleared for tillage and sheep, and clays bearing forest for raising animals, which is also characteristic of the Iron Age. There is another separate set of earthworks known as the north Oxfordshire Grim's