 A <unk> line of <unk> and <unk> can be found on both one of the central kerb @-@ stones on the western end of the monument and a kerb @-@ stone on the south @-@ east of the monument . These have been attributed to the <unk> of flint and other stone axe @-@ <unk> on these sarsens . It is possible that these tools were sharpened for use in cutting and carving the timber <unk> and struts which would have been used in <unk> the stones and constructing the tomb . Similar evidence for the <unk> of tools has been found at West Kennet Long Barrow , as well as later prehistoric monuments such as Stonehenge . 
