Here is the final version of the captions. Please do not object unless there is some dreadful, dreadful error as the Calendar will be going to proof this week and any prolonged discussions may cause a delay of a couple of months!
On balance of opinion, Darkstar's pic has been labeled as being in in 'Browns Folly mine' on the basis that (i) it seems to be commonly known as that; (ii) Clunk has a survey which calls it that (admittedly as a section of Monkton Farleigh); and (iii) given the fact that there are two other Monkton Farleigh pictures in there, a bit of variety would be nice ;)
Ferret: "Crab winch, Cliftworks area of Box Freestone quarry"
Miles: "Limestone bridge, Milwr Tunnel"
SimonRL: "Winch, Blaenau Ffestiniog slate mine"
Barney: "Haulage floor, Blaenau Ffestiniog slate mine"
Nimrod: "Artefacts in the top level extension, Coniston Copper mines"
Vanoord: " 'Lefel Dwr' drainage tunnel, Blaenau Ffestiniog"
Clunk: "Crane, Cliftworks area of Box Freestone quarry"
Mole: "Reserve explosives station, Carrock Wolfram (Tungsten) mine, Cumbria"
Dark Prince: "Conveyor, Monkton Farleigh District 20"
Tin Miner: "Old Wagon, bottom level cross-cut of Bellan Mine, Cornwall"
Darkstar: "Mine pearls, Browns Folly mine"
Mike Leary: "1938 abandoned workings, Monkton Farleigh quarry"
Hello again darkness, my old friend...