I was expecting the Welsh Valleys to be littered with remnants of the coal and steel industry. In fact, almost all traces of the former industries have been completely erased - the buildings demolished and the slag heaps landscaped into country parks for mountain biking and such like.
In December 2000 UNESCO named the Blaenavon Industrial Landscape as a World Heritage Site for the following reason:
"The area around Blaenavon bears eloquent and exceptional testimony to the pre-eminence of South Wales as the world's major producer of iron and coal in the 19th century. All the necessary elements can be seen, including coal and ore mines, quarries, a primitive railway system, furnaces, the homes of workers, and the social infrastructure of their community."
We visited both the Iron works and the Big Pit coal mine.