Thanks to Richard Hill for alerting us to this temporary hazard:
“There is a rotting sheep lying in the [Nedd Fechan] surface stream just below the [road] bridge at Bridge Cave. You won’t notice it before you go into Bridge Cave but it is lying in the water which feeds directly into the Waterfall passage in the cave. So maybe best not to drink the water! You will notice it if you carry on downstream to the other caves.”