The slate industry in Wales is usually associated in everyone’s mind with the area in the north west of Wales, especially the region around places like Blaenau Ffestiniog and Bethesda.

In fact, for many years there was a thriving slate industry much closer to home, especially in the Berwyns to the west and south of Llangollen, and indeed slate products are still produced today in the Horseshoe Pass area to the north of Llangollen.

In the Berwyn mountains slate production left great heaps of waste material and huge underground caverns. They are always referred to locally as slate quarries, whereas in reality they should be called mines, since the production mostly took place underground not on the surface as in a quarry. If one is lucky enough to visit one of these vast caverns it is a humbling experience.

But first one has to be mindful of perhaps three things. Firstly, it is important to remember that someone owns the land on which the ‘quarry’ is situated and it is essential to have their permission; secondly, you need to be accompanied by someone who knows what they are doing and where they are going (and how to get out again!); and thirdly, you have to wear a hardhat.

Very few of the old quarrymen wore any headgear more protective than a flat cap, but they had a lifetime’s experience. In the mine the first thing that you notice is the dust that seems to hang in the air. Lung disease was a constant risk, as was rheumatism because of the damp. On a summer’s day it is also cold down the mine, a fairly constant temperature that in the winter could be warmer than working on the surface.

The other thing is the total dark, a complete blackness that means one is in real trouble if the torches fail. In the old days the quarrymen made do with a tallow candles stuck in a lump of clay.

All in all it is a memorable experience that fills you with admiration for what the slate quarrymen used to do for a labourer’s wage of £4 a week plus 3d (slightly more than 1p) a ton bonus for moving the rubble.