The excellent ‘Hampshire Treasures’ resource gives the following information – “CastlePiece. Probable Hill Fort. Earthwork encloses 41/2 acres. Entrenchments are well spread but clearly defined gap in south east side is probably the original entrance. O.S.A. No. SU10 NE18. Ref: 1. Field Archaeology as Illustrated by Hampshire, 1915, (Williams-Freeman), p.170, p.433. Ref: 2. Ancient Earthworks in the New Forest, 1917, (Sumner), p.26.” This is a scheduled ancient monument no.229.