A range of evidence marks the operations of the Neufang mines located at the Geisingberg. The mining of tin lodes from the 15th to the 18th centuries is documented by the oldest waste heaps, the mining claims still marked by some original boundary stones. Located separately, the powder house (est. 1793) was used to safely store the gunpowder for blasting underground that superceded (or in many cases supplemented) the method of fire-setting. It was divided into four chambers that segregated the major Altenberg mining companies, and a fifth chamber that was leased by the miners’ guild.
Zwitterstock Tiefe Erbstolln was developed from 1491 to 1543 to provide a long-term and cost-effective solution to drain Altenberg’s Zwitterstock, the most significant tin deposit in central Europe. The 1,978-m-long adit is one of the technical masterpieces of the Ore Mountains, and it took more than 50 years of strenuous and highly dangerous manual labour to advance the adit using the technique of fire-setting (gunpowder/black powder had not yet been introduced). A 1,700-m-long accompanying tunnel ran above the adit to provide the air circulation necessary for combustion and ventilation, connected to the main adit at multiple points that purged all discharge air through ventilation openings. Pumping systems enabled extraction of tin ore to a depth of 120 m below adit. The adit was in continuous operation until 1982, following which it now acts as a natural mine-water drain that serves the Altenberg ore deposits of Geisingberg and Zwitterstock.