On our Herefordshire fieldwork project we camp on the local Dorstone village playing fields behind which runs an old straight track. On a dog walk last year I noticed a section that had some inclusions with conchoidal fractures.
I stored this in my memory bank, and this year ended up going on a super impromptu walk with a group of students interested in lithics. The aim was to introduce them to the art of finding knappable materials in the landscape (something I am getting good at).
Anyway, as well as an opportunity to all get to know each other a little better, it turned out to be a surprisingly enjoyable material locating and testing exercise.
I told Tim Hoverd, Herefordshire County archaeologist, about our adventure and he pointed out that this particular old straight track used to be a railway line, hence the glass slag that we were finding. I wanted to end this post with some kind of witty Alfred Watkins reference. However, I have now ended up reading about the Golden Valley Railway on Wikipedia. C’est la guerre.