Can Any One Tell Me?

A Memory of Glyndyfrdwy.

Spent a while looking at Glyndyfrdwy on Google maps and came across 3 areas just below Glyndyfrdwy that look like very large limestone mounds. There appears to be derelict remnant of miners? houses by these rocks. The area looks fascinating and well worth a visit for photography!

Would be so grateful though if someone can cast a light on these limestone areas and their ruins. Whether they are old quarries or mining communities - - help please!