The rounded tip, straight butt and slightly convex edges of the Castle Lane Farm handaxe give it an almost triangular shape, known as sub-triangular. It was made from a large piece or flake of flint, with one face trimmed flat and the other slightly domed. The sides and butt have been neatly finished by knocking off small flakes to make strong, low-angled edges. This retouch suggests that all of the sides may have been used to cut and slice. The straight edge is like that of an axe but does not show any damage, which would have occurred while chopping a hard material. Like most other handaxes of this kind, it was found on its own without any other artefacts or bones. Handaxes with the same distinctive shape and features have been found at Coygan Cave in Wales, in deposits dated to the early to middle part of the last Ice Age, some 80,000 to 40,000 years ago. At this time southern Britain was inhabited by Neanderthal people. This type of sub-triangular handaxe with convex edges is a marker of their presence in Britain. It is a kind of handaxe unknown in Neanderthal toolkits elsewhere in Europe.