Main content
The largest underground slate quarry in the world!
Will witnesses first hand the immense scale of the 200 year old, Cwmorthin Slate Quarry, and finds something he wasn't expecting.
Duration:
This clip is from
More clips from Hidden Wales with Will Millard
-
![]()
Going deep underground in Wales—Series 2
Duration: 03:13
-
![]()
The 'new' Elan Aqueduct—Series 2, Episode 6
Duration: 02:38
-
![]()
WW2 Aircraft Wrecks in the Brecon Beacons—Series 2, Episode 5
Duration: 02:49
