The SGLR is situated in one of Derbyshire's most dramatic landscapes, with easterly views across Black Rocks, an outcrop of gritstone famous for climbing since the last century. To the north, the landscape plunges into the Derwent Valley with distant views of Matlock and the moors beyond. To the west Middleton Moor dominates the skyline, a source of limestone quarrying since the mid 1800s.
Greenbat and manrider traveling towards Dark Lane Quarry It is to this hill that the railway was originally constructed in 1884, to exploit the high grade limestone prized for ornamental work, although the quarry opened in 1845.
The steep-sided cutting that the line passes through is of Carboniferous Limestone laid down as mud some 330 million years ago in a warm tropical sea when this part of Britain was south of the Equator. Further up the line beyond the tunnel at Dark Lane Quarry, it is possible to see some of the fossils of animals that lived in this ancient sea. Crinoids (sea lillies), rather like stalked starfish, corals and brachiopods (ancient shellfish) are found most frequently on the rock faces and on the bedding planes (flatish surfaces of the rocks which represented the sea floor in the distant past). The rocks also have numerous joint fissures or cracks caused by ancient movements of the earth's crust, which have subsequently been filled by minerals around 180 million years ago, long before the demise of the dinosaurs.
The most common minerals to be seen are barytes (barium sulphate), calcite (calcium carbonate) and galena (lead sulphide). The latter mineral has been extensively worked from medieval times onwards in the surrounding fields to the railway. Many leadmine shafts can still be seen.
ZM32 at Killers Dale Dark Lane Quarry was worked during the construction of the original standard gauge railway, and some shot holes can still be seen on the high rock face after the tunnel on the north side. Most of the small quarry was however worked by 'plug and feather', a way of breaking the rock into blocks using large hammers and iron wedges. Blasting was not normally used in the quarry proper as this would damage the stone and make it unsuitable for ornamental use and building stone.
Limestone areas often have a rich profusion of wild flowers, and the SGLR is no exception. Many of the surrounding fields too are of great wildlife importance and are designated Sites of Special Scientific Importance (SSSIs). The adjacent National Stone Centre is also an SSSI primarily for its geology, although this too has well over 120 different species of plant already discovered within the old abandoned quarries. The more shaded sections of the railway are dominated by plants such as mosses, lichens and fearns together with an extensive cover by the diminutive geranium called Shining Granesbill, easily recognised by its reddish coloured stems and shiny roundish leaves with pink flowers. At the bottom end of the line and by the old Porter Lane, a wild snapdragon called Toadflax can be found, with yellow flowers. Another very distinctive plant (at least by its smell) also occurs at the High Peak Trail end of the railway, Sweet Cicely, with a very distinctive smell of aniseed. Actually, it is closely related to parsnips and carrots, being a member of the wild carrot family.
The cutting is a blaze of colour in the late spring with other flowers such as the common red campion, knapweed, ox-eye daisies and wild dog-roses. Once beyond the tunnel where light penetrates to the banks of the railway Cowslips can still be found, whilst further on in the shade below the mature trees planted by the railway company many years ago the uncommon broad-leaved Helleborine thrives with its dull red flowers. Because the railway is not only the habitat for all these flowers, but also for rabbits, foxes, voles and even barn owls, great care is taken by members of the society to look after and treasure this wonderful spot.