Estimated Grid Ref. The only documented mention (Hamilton Jenkin) of this mine dates back to May 20, 1836, in the West Briton. Identified in 1954, there are two adits and a backfilled shaft located near the bend of the road southwest of Roskilling hamlet. The grid reference provided is centered on this area. It’s worth noting that while the Constantine museum website spells the name as ‘Bosaneth’, this appears to be an error, as the adjacent mill downstream is spelled ‘Bosanath’ on the 1908 Ordnance Survey map.