Big Pit The Big Pit is part of a network of coal workings built in Blaenavon in the first half of the 19 century by the Blanaevon Iron & Coal Company. It was part of the development of the Blaenavon Ironworks, and has some of the oldest large scale industrial coal mining developments in the South Wales Coalfield.The mine was the most important of all the collieries located in Blaenavon. Limited Edition: 195 Image size: 30 x 30cms (paper size 35.5 x 35cms approx) Price: £85 Share on Facebook or TwitterShareTweet