Croes y Ddwy Afon again, an intriguing method of capping (or at least we presume it is). The boulders seem to be blocking the top of a chamber.
Photograph:
🔗Croes-y-Ddwy-Afon-Slate-Mine-User-Album-Image-004[linkphoto]Croes-y-Ddwy-Afon-Slate-Mine-User-Album-Image-004[/linkphoto][/link]
my orders are to sit here and watch the world go by