They are the Tankardstown copper mine workings at Knockmahon.
We couldn't go in but could walk all around the area. There were seats there too so we could sit and enjoy the view.
Moving on again and yet another beach to stop at for photos.
The sea mist was starting to roll in, but it had stayed dry all day!
Time to go back to the B&B for a shower and get ready to go out for our evening meal.