Peacock's Farm in the parish of Shippea Hill, Cambridgeshire, is situated in the SE. corner of the Fenland some 7 miles ENE. of Ely and about 20 miles almost due south of King's Lynn. The position of the site is shown in fig. 1, in which areas of alluvial deposit are reserved and more ancient deposits are obliquely shaded, marking the margin of the fen basin and in places islands, which break the monotony of the level fen. Crossing the map obliquely in the bottom right-hand corner is the Icknield Way, marked by a solid line where its course is certain and by a broken line where it is less well defined; and situated in immediate proximity to this ancient track on Therfield Heath, near Royston, is the only Long Barrow at present known in the region. A corner of the modern Wash is shown at the top of the map for convenience, though actually the sea was very far away in the Mesolithic and Neolithic periods. The river system marked on the map is based entirely upon the work of Major Gordon Fowler, F.S.A., F.G.S., and indicates fairly certainly the system which functioned during the Mesolithic and Neolithic periods, or rather that part of the river system of these periods still available for study above the sea. It will be observed that all the rivers shown on this map form tributaries of a single great river, flowing through the present site of Wisbech, through the estuary in the sixteenth-century coast line (shown by a broken line), and by way of what are now known as the Lynn Deeps and Silver Pit out across the present North Sea, to reach the contemporary coast-line.