Tool marks at Grimes Graves, Weeting, Norfolk
The marks on the chalk wall of Gallery III1 in Greenwell's Pit appear to have been made by a ground stone axe made of a stone whose source lies some considerable distance away, an example of which was found amongst the antler picks during excavations in 1868-70. Why the Neolithic miners used a rare imported stone axe to mine flint for axes remains a mystery. This site is now in the care of English Heritage (2010).