LocationSH 670 465
DirectionsFrom Blaenau Ffestiniog, head to the power station and drive up the hill right to the highest/farthest point you can and park at the parking area immediately before the gate across the road (above Tanygrisiau)
Walk up the road until you see a footbridge over the stream on the left and take the footpath there that follows the footpath up stream. Continue past Llyn Cwmorthin and head upwards to the slate spoil heaps (staying on the footpath).
As you approach the gully, you can see three recesses in the mountain just above the path – these are exposed slate chambers of the mine (although there are actually 5 – you can only see 3). They also become invisible as you approach. There is also an adit just below the path in the same place which is also not visible until you are stood over it.
AccessUngated. Permission requirements unknown.
Suggested EquipmentFull SRT if abseiling in or be prepared for waist high water in the lower adit. Other equipment requirements are unknown.
LengthUnknown.
Flood riskNot known.
Mine AttributesSlate
DescriptionVery little is known about this mine other than it is believed to be over-shadowed by it’s illustrious neighbours Cwmorthin and Rhosydd.
Of the adits/Chambers photographed below, one is underneath the path and is consistent with a drainage adit (and is flooded to 6-8 inches) but is believed to allow entry to the system.
Some of the exposed slate chambers above the path have suffered collapses making them impassable. One such chamber has an adit high on the read face which appears to be unreachable.
There is also an another adit alongside these chambers (up hill end) which travels for around 100feet before materialising at the top of a slate chamber. This is bolted (an old bolt) and is presumed to be the abseil entry point.
Unexplored PassagesThe drainage? entry? Adit remains unexplored.
The entry adit to the abseil is unexplored beyond the abseil.
It is possible there are other unfound entrances.
DigsNone Known
Linkshttp://www.mine-explorer.co.uk/mines/Conglog_178/Conglog.asphttp://www.jgd.org.uk/rotwsi/conglog01.htmhttp://www.aditnow.co.uk/mines/Conglog-Slate-Mine/http://www.rhs.ac.uk/bibl/wwwopac.exe?&database=dcatalo&rf=200711893&SUCCESS=false&SRT2=ti&SEQ2=ascendinghttp://www.frheritage.org.uk/wiki/Congloghttp://www.cowdery.org.uk/conglog.php