Gersdorf mining landscape is located 19 km NNW of the Freiberg mining town and contains the Segen Gottes Erbstolln mine (silver mine, 12th century to 1885) with its integrated network of underground and surface elements. The property is typical for the Freiberg Mining Landscape and extends from a high plateau (administration and mining area) via a ridge of small hills to a steep descent of the northern flanks of the heavily wooded Gersdorf Hill (mining area) to the floodplain and the Freiberger Mulde river (processing and transport area). The river, in its easterly meandering course in a rural setting between Rosswein and Nossen, and the southern half of its floodplain where adit drainage, water management (including stone weir) and silver washing sites are located, is also included. It is part of the component part of the Freiberg Mining Landscape (4-DE), to which it is connected underground by a water supply system and connected on surface by the Freiberger Mulde River to the Freiberg central mining district.
The property is remarkably authentic and comprises an impressive silver mining landscape that contains the complete area of centuries of operations. In general, it has not suffered from modern intrusions, and remains unthreatened. Originally the mine belonged to the nearby Cistercian Monastery at Altzella, its name deriving from Heinrich von Gersdorf who, in 1547, was the first chief official of the Saxon Mining Office. In the 17th century the mine was the largest and most important silver mine of the district, employing 400 persons. The archaeological remains and underground structures bear outstanding testimony to the successive development of mining technology and the influence of the prevailing mining law from the 12th to the 19th century. High functional integrity is demonstrated in two principal and outstanding late 18th and early 19th century technological ensembles for pumping/de-watering (waterwheels and flat-rods, superceded by more efficient water-column engines):
• Two parallel, flat-rod inclined pumping and hoisting systems that served Wolfgang and Joseph Schacht (shafts, built 1791/1810 and in use to 1863), including their water supply ditch, wheel pits, inclined course of flat rods with two parallel masonry tunnels and twin arch entries into Joseph Shaft.
• Water-column pumping system serving Joseph Schacht (shaft, 1833 and 1863), including underground in situ water-column engines (hydraulic water pressure engines) in a fine masonry engine and balance chamber adjoining the shaft, surface shaft-head buildings and the water supply leat.
Integral to the water power ensembles is the underground adit system (built since 1680) used for the water exhaust from the water-column engines, and their mine drainage from lower workings (now flooded), together with the earlier discharge route from pumps in Jospeh Shaft that were operated by the eastern flat-rod system. In addition to the main adit level, with air shafts arched over in dry-stone masonry, there are drives on the lode that show good mineral vein exposures in small stoped areas. Access to around 15 km of workings is facilitated by a reconstructed false floor of traditional timber crossbars that use original rock ‘hitches’ to support a manway of longitudinal timber planks extended laterally to create a false floor above an unobstructed waterway that discharged into the adit ditch/canal, contained within the property, to the washing works and finally into the Freiberger Mulde River. Other modern safety and conservation works include brick arches, reproducing the original design and materials used in the 19th century and preserved elsewhere in the mine
In Joseph Schacht, at the level of the Adam Stolln (adit), two cast-iron water-column engines (built 1833/1863), represent a remarkable survival of pumping equipment that is relatively complete and in its original location. These are set in an architecturally fine, and visually impressive, masonry engine chamber and balance chamber. Such technology enabled the mine to achieve its highest yield (1.8 tonnes) of silver in 1851. Joseph Schacht is capped at surface but many interesting structures remain well-preserved, including the exposed shaft masonry, remains of the sorting place, and the ore pass.
The inclined courses of two lines of reciprocating flat-rods (built 1791 and 1810) are approximately 250 m and 335 m long, the latter passes through a tunnel. The rods were powered by waterwheels just above the Freiberger Mulde River and operated pumps in the shafts which discharged mine water to adit level. There are two well-preserved stone masonry-lined leats that brought water to Joseph (Higher Leat, built 1844) and Wolfgang (Lower Leat) shafts. The water reservoir of the Untere Krebsteich (built 1743) also survives. The primary mining landscape also contains numerous heaps of waste rock from shaft sinking, development and low-grade ore (small heaps from medieval and 16th/17th century smaller shafts, larger heaps from 18th/19th century larger shafts) interspersed among shaft depressions. Most of the waste heaps and shaft depressions (some 200 in total) follow the strike of the ore veins and date back to the Middle Ages. Medieval mining concessions are packed closely next to one another. Shaft depressions and waste heap courses extend along all ore veins that outcrop at surface, often merging seamlessly into one another. They sometimes also run parallel to one another at a distance of a few metres. The extant mine-road once led to the mine administration buildings and to a settlement of around 1,000 people.
This important complex of mine buildings is located at the top of the hill and is centred around the administration building (Huthaus), a two-storey half-timbered building that was originally a hoisting house for a horse-gin, and a courtyard. Adjoining is the mine forge (now a dwelling), a two-storey building with rubble-stone ground floor and half-timbered first floor that dates from the 18th century.