Searching for some background information in Wikipedia I stumbled upon this link to a George Orwell's article about his visit to a coal mine:

When you go down a coal-mine it is important to try and get to the coal face when the ‘fillers’ are at work. This is not easy, because when the mine is working visitors are a nuisance and are not encouraged, but if you go at any other time, it is possible to come away with a totally wrong impression. On a Sunday, for instance, a mine seems almost peaceful. The time to go there is when the machines are roaring and the air is black with coal dust, and when you can actually see what the miners have to do. At those times the place is like hell, or at any rate like my own mental picture of hell. Most of the things one imagines in hell are if there — heat, noise, confusion, darkness, foul air, and, above all, unbearably cramped space. Everything except the fire, for there is no fire down there except the feeble beams of Davy lamps and electric torches which scarcely penetrate the clouds of coal dust.

There's without doubt a lot of non-fiction works from some of the most renowned writers that remain away of the common knowledge, yet they provide views about the most diverse topics with an uncommon literary quality that would make them particularly appealing for any reader. This is surely one that you shouldn't miss.