I can't seem to upload the last two piccies ....
The adit was off a footpath (I followed a stream upwards to a likely looking area) - I was near Bryn Rhyd Yr Arian having a wander.
The entrance was over wellie depth but a swift drainage channel quickly dropped the level by a few inches.
I thought it was going to be a trial as there is nothing at all marked on the map - no level, no mine, no tip - nothing - but it wasn't. It was actually a small mine.
Inside it was a surprise, it went for around 300 metres with numerous spurs all blocked with stacked deads except one which was passable although I did not crawl though.
The passage had some decorations - possibly iron/copper. Some calcium straws were forming.
I could not guess what was being mined here - I would have thought lead but a nearby isolated copper mine might suggest this was copper too although I found no evidence of it.
Rather an odd thing really .... quite a billy bonus for a wander out in the fields though
Ian