Sondershausen, a medium-sized town of about 20,000 inhabitants, lies about 50 km. north of Erfurt in the land of Thüringia. Prospecting for potash began in the closing years of the nineteenth century and the first shaft of what became the Glückauf mine was completed in 1895. Two years later a potassium chloride plant was opened nearby to process the mine’s products. The mine was extended in subsequent decades and in 1937-38 two new shafts were sunk for the War Ministry. After the Second World War Sondershausen was incorporated within the GDR and from 1947 the mine was owned by the land of Thuringia. It was employing 3,000 people in 1989, but that was its last year of full-scale production, and it closed two years later.
In 1995 it passed to a company that proposed to develop it as an adventure mine, something that would have been almost impossible in a less stable coal mine. Some rock salt is still extracted for application to icy roads in wintertime. From 1999 visitors were able to slide down a spectacular salt chute, and from 2001 wooden barges from the River Spee were used to give rides on an underground lake, the Laugensee. An underground concert hall was opened in the same year, and an underground bowling alley in 2004. An underground banqueting hall can seat 60 diners. Since 2007 there has been an exhibition showing military activities in the area before and during the Second World War. The surface buildings and the headstock are well-preserved, and the mine’s power station has a particularly magnificent generating hall.