Kalibergbau Museum Volpriehausen

Useful Information

Location:	Wahlbergstr. 1, 37170 Uslar-Volpriehausen. (51.667245, 9.740305)
Open:	MAR to OCT Sat 15-17. [2026]
Fee:	free. [2026]
Classification:	Salt Mine
Light:	Electric Light
Dimension:
Guided tours:	self guided
Photography:	allowed
Accessibility:	no
Bibliography:
Address:	Kalibergbau Museum Volpriehausen, Wahlbergstr. 1, 37170 Uslar-Volpriehausen, Tel: +49-5573-541, Tel: +49-5573-555.
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then. Please check rates and details directly with the companies in question if you need more recent info.

History

1895	The Justus I mining union founded in Cologne.
1896	Successful deep drilling.
1898	Start of sinking of shaft Justus I.
1901	Shaft completed, surface facilities constructed.
1904	Potassium chloride plant commences production.
1906	The Justus mining company is converted into a public limited company based in Volpriehausen.
1915	Company and shaft renamed Wittekind.
1915	Hildasglück shaft completed.
1921	Potassium chloride factory shut down as a rationalisation measure.
1938	Potash mining ceases, army munitions factory is established.
29-SEP-1945	Devastating explosion.
1985	Potash Mining Museum founded by members of the Volpriehausen Local History Society.

Geology

The North German Plain consists of approximately 4.5 km of Mesozoic sediments. The formation of basins led to the intrusion of the sea across large parts of Europe, and a wide variety of sediments were deposited in these shallow inland seas. The base of these sediments is crystalline bedrock. Overlying this are rocks of the Zechstein, the earliest period when seawater penetrated the new basin. At that time, the connection was not permanent; seawater entered and evaporated in the arid continental climate. Thick layers of gypsum, rock salt and potash salt formed, and this sequence was deposited in multiple layers.

Much later, following a phase of subsidence and deposition, uplift occurred once more; the sea became land, and erosion set in. This movement led to the formation of faults and fault zones, causing the rocks to crack. Salt is lighter than normal rock; moreover, it is plastic under high pressure and temperature, so it began to flow and rise. It made use of the fissures, and thus salt rose to the surface. Salt is lighter than normal rock; moreover, under high pressure and temperature it is plastic, so it began to flow and rise. It used the fissures for this, leading to the formation of salt diapirs at fissure intersections, as well as salt walls along fault zones.

Mining is based on the fact that salt-tectonic structures reach the surface throughout the North German Plain. In some cases, they are reached by groundwater, forming brine springs from which salt was extracted through evaporation and distillation. In other cases, shafts were sunk and the salt mined underground. As a rule, both rock salt for human consumption and potash salt for fertiliser production and the chemical industry are found. Depending on which is more common or has been mined more extensively, the term used is either ‘salt mines’ or ‘potash mines’.

Description

The Kalibergbau Museum Volpriehausen (Volpriehausen Potash Mining Museum) is a mining museum dedicated to salt and potash mining. The discovery of potash salts and their great importance as a natural fertiliser for agriculture by Justus von Liebig and Adolf Frank in the mid-19th century laid the foundations for potash mining. Of course, salt had already been mined previously for human and animal consumption and for food preservation. However, potash mining did not begin until the end of the 19th century. Accordingly, the exhibition focuses on the history of potash mining in southern Lower Saxony from 1895 to 1960. The Wittekind-Hildasglück double-shaft mine was located in Volpriehausen. It was built by the Justus I mining company, founded in Cologne in 1895, following successful deep drilling in 1896. The Justus shaft was constructed between 1898 and 1901. Five mining levels were established at depths of between 480 and 540 metres. The surface facilities, such as the winding engine house, the shaft hall with winding gear, the raw salt mill, the boiler house and the electrical substation, were then built. A potassium chloride plant for processing the potash salt into fertilisers was also built, which commenced production in 1904.

A second shaft complex, Hildasglück, is somewhat younger. In this area, deep drilling had yielded only moderate potash deposits. The Justus mining company bought out the owner, the Hildasglück mining company, in order to sink a second shaft for the potash works. Work on this began in 1910 and reached a depth of 160 m in the very first year. However, there was also a problem: heavy water inflows made special waterproofing necessary. In 1915, the final depth was reached and levels at 794 m and 917 m were sunk, connecting the two shafts. The shaft served as a ventilation shaft.

Another aspect is the Wehrmacht’s use of the disused Wittekind potash mine as an army munitions depot (Bw) between 1938 and 1945. The site had already been offered for rent to the Wehrmacht by Burbach-Kaliwerke in 1936. When the Wehrmacht accepted the offer, mining operations in Volpriehausen were ceased in 1938 and the facilities were converted. Production was originally carried out above ground, for which 12 factory buildings were constructed in the woodland between the two shafts. In 1940, the manufacture of infantry grenades began. Subsequently, an increasing number of forced labourers, prisoners of war and internees from the Moringen youth concentration camp were conscripted into munitions production. When the Allied bombing began, production was moved underground. From 1944 onwards, cultural artefacts were also increasingly stored in makeshift facilities in the deeper parts of the mine. These came from the surrounding area, for example parts of the library of the nearby University of Göttingen. However, following the liberation of the forced labourers and the occupation of the site by the US Army, looting and damage occurred. As there were still around 20,000 tonnes of explosive material underground, this was extremely dangerous. And indeed, on 29 September 1945, a devastating explosion occurred. It took almost a year before the shaft could be accessed again on a temporary basis and some of the cultural artefacts recovered. This was a last-minute rescue, as seeping groundwater flooded the tunnels, making any further recovery impossible. The remaining cultural artefacts have long since been destroyed by the salt water. Today, nothing remains of the mine shafts, and the factory buildings have also disappeared. There are still a few workers’ houses and the director’s villa from the mining era.

The museum opened exactly 100 years after the founding of the mining union Justus I, and was in fact the first museum dedicated to potash mining in Germany. It has been run by the Heimatverein Volpriehausen e.V. (Volpriehausen Local History Society) ever since. The focus here is on geology, mining, the daily and working lives of the miners, and the technology used for extraction and processing. A highlight is the mineral collection. In addition, other related industries in southern Lower Saxony are also presented. Part of the exhibition is dedicated to the Volpriehausen Army Munitions Depot (Bw). But the museum has neither an underground section nor an artificial tunnel. The buildings in the town that still exist can be visited on a mining tour.