BLAENAU FFESTINIOG, Gwynedd, Wales — The middle of Wales, near Snowdonia National Park, looks just like the Shire.

You can almost expect to see Frodo Baggins round the bend on a wagon. The hills are like green jewels. There are arching bridges over babbling brooks. The wide, grassy meadows are bordered by miles upon miles of slate walls.

The slate is everywhere. This is mining country, and slate is the commodity. You can tell where it’s been mined the heaviest. In those places, the hills have been turned into mountains heaped with the rubble and refuse left over.

Instead of looking like the Shire, the mining towns look like Mordor. We took a tour deep into the belly of one of these mines at the Llechwedd Slate Caverns. I expected a decent, overpriced walkthrough of a few caverns, with a brief chronicle of the slate industry that boomed during the Victorian time, when slate roofs were the rage all around Europe.

Instead, we walked through the lives of generations of Welsh men who carved out a livelihood in these caverns for 12 hours a day. Paid 12 pence per week, they received three days of vacation per year. They pounded the rock by hand with a 7-foot iron pole, often hanging from the rock face by a chain wrapped around their leg. At the end of the day, they blasted their chunk of slate out of the rock face with gunpowder and went home for the evening.

If done right, they came back in the morning and found a useable hulk of slate to load onto their wagons. They hauled the rock to the top in carts, split it into tidy shingles and shipped it by the crate load out of the country. For every ton of saleable slate, there could be up to 30 tons of waste.

The miners worked in teams of four, and they policed each other underground as one would police a village above ground. During lunch, they talked family life, village life and politics. The first unions in Wales came out of these meetings. Sometimes they sang in their lilting Welsh tongue.

Slate mining was the livelihood of the dead and dying. Boys as young as 8 worked the mines with their families. The job was tedious and dangerous. Our guide’s grandfather lost the use of his good hand during an accident with the gunpowder. Most men had to retire by 45, victims of the lung disease silicosis. By 50, they were dead.

Grid View Asher Lewis in the Llechwedd Slate Caverns. The mine has 25 miles of excavated passageways and caverns underground. Tiffany Gee Lewis

An old mining cart sits on the underground track. The slate was loaded onto these carts and hauled up for splitting. Tiffany Gee Lewis

The Llechwedd Caverns have 25 miles of excavated tunnels and caverns. The size of these caverns is staggering. In the dim light, they resemble damp and dripping cathedrals. Most miners spent their entire lives working in the same cavern, chiseling away from left to right, bottom to top, in air that hovered near freezing year-round.

Our mine tour lasted one hour. When we emerged into the light, the sun stung our eyes. The air wasn’t overly warm, but it felt positively tropical after the chill from below.

It’s funny how you can go down as one person, and come up changed. Before visiting Llechwedd Slate Caverns, I knew nothing about slate and the miners who dug it out of the earth. Since then, I see slate roofs everywhere, on churches and schools and row houses. I point them out to the family. I feel this need, this urgency, to appreciate and remember the work of these men.

Like all of us, the slate miners lived, they provided for their families, and they died. Surely there was joy, glimmers of hope, snatches of laughter, even in the dark. But it was hardscrabble living, plain and simple. You can see it on the faces of the next generation, as they try to dig their way out of the past and into the light.

It seems a story worth telling. I’ll never look at slate the same again.

Tiffany Gee Lewis is a freelance journalist and children’s book writer. Based in the Pacific Northwest, she and her family are on sabbatical for a year in Oxford, England.