By the early 1960s, the strategy of the
National Coal Board meant that all of East Lothian's and most of Midlothian's collieries were earmarked for closure. At the same time, within the coalfield community, there was an awareness that technology and culture was also changing and much that was of significance was in danger of being lost forever. Prestongrange Colliery had closed in 1962 and the site began to be cleared. However, work stopped when a new plan to turn the site into a museum was adopted. The museum was the idea of David Spence, a retired mining engineer. A steering committee was formed in 1968. Volunteers worked to clear the site and assemble exhibits. The National Mining Museum was formally launched at Prestongrange on 28 September 1984. Prestongrange had three key merits as a museum site. First, the estate features in the earliest written account of collieries in Scotland, often dated to 1180–1210. Second, the existing colliery included the first deep shaft in Scotland, which
Matthias Dunn of Newcastle sank in 1830 to the Great Seam at . Third, the colliery housed the last Cornish beam engine remaining in situ in Scotland. Artefacts were collected from around the coalfield and stored at Prestongrange. The interior of the beam engine house and the colliery power station became galleries. With the closure of Lady Victoria Colliery at
Newtongrange in 1981, the ambitions of the steering group expanded to include that site. After operating together from 1984 to 1992, Prestongrange was withdrawn from the National Mining Museum by East Lothian District Council and recast as Prestongrange Industrial Heritage Museum to encompass the area's other once significant but vanished industries –
salt boiling,
chemical synthesis (particularly
sulphuric acid),
soap making,
glass making,
potteries, industrial ceramics and bricks. ==Main features==