Wales is known as the first industrial nation in the world, and a lot of that is down to the development of the mining industry. There is more to mining than coal of course, and the north of the country was the most important slate-producing region on the planet. The Dinorwic Quarry near Llanberis was one of the largest slate mines on the planet so it is only fair that it is the location of the National Slate Museum, a charming love letter to the proud history of slate mining in the area. The museum holds plenty of events throughout the year, and entry is free.