Dear Alisdair, The Middletown Mine was an interesting place one way and another, not big, of course, or extensive, but an interesting local. all the same. To the best of my knowledge, there was work being done for barytes on the place around 1977, and it did entail both surface and a little u/g work. I happened to know the haulage co. that operated from the largish building below (and buy the main Welshpool/Shrewsbury road - defunct for some 7 yrs. + now), and it was he who told me about what was going - and this about 1977. I haven't visited the place, but have passed it many times over the years, but have always taken note of visual changes there - of which there have been some on the hill. Whereabouts exactly is the Bulthy Mine? - distance/dir. from Middletown. Regards, Bernard