I love accidental archeology like this. My colleague at work, Marianne, knowing of my academic background, had been talking to me all week of this mystery object she found lying in a path while walking her dog near her village. She struggled to describe it. It was sort of brass/bronze/coppery, heavy and hollow, she explained unhelpfully. So, finally she brought it into work for me to look at properly. It is half of a broken 'looped and socketed' axe head from the Bronze Age. See a similar one here.