REASONS FOR DESIGNATION
The Pin Dale side veins are believed to be a nationally unique feature, demonstrating the response of miners to local geology. The side veins are well-preserved, with toolmarks still clearly visible in places, and are a distinctive landscape feature. Although they are themselves unparalleled, their low-technological response to difficult geological conditions is a feature characteristic of lead mining in Derbyshire. The side veins will contribute to an understanding of the wide range of mining activities which took place in the Derbyshire orefield.
The monument lies on and around a near-vertical valley side, 1km south east of Castleton, and includes all the earthworks and buried remains of the Pin Dale lead side veins. The extraction of lead-bearing strata from extremely narrow veins, close to the surface and surrounded by limestone, left a number of narrow vertical slits in the limestone orebody, which exist alongside more typical shaftmounds. The side veins represent a form of opencut lead mining, which demonstrates the response of miners to an unusual form of mineralisation. The side veins are a series of well preserved, narrow slits (some only 0.4m wide) cut by hand from the surface of limestone crags into lead-bearing veins. Tool marks are clearly visible in some. They appear now as open slits or channels of varying length. Some are between 2m and 3m long, whilst others are cut through extensive stretches of limestone and have the appearance of narrow quarries. In some cases parallel cuts have been worked around a core of limestone, leaving large isolated blocks as a particularly distinctive feature. In addition to the side veins, a number of vertical shafts are included in the scheduling. These appear as small shaftmounds or in some cases as open shafts. A number of spoilheaps, relating to both side vein and shaft workings, are also included. Buried remains will include dressing areas, where early stages of ore processing were carried out, whilst the spoilheaps will provide further technological information on mining activities.