Active iron ore open-pit mine at Eisenerz, Styria, open to visitors via underground show mine, Hauly truck tours, and open-air exhibition, operating as Abenteuer Erzberg.
The Steirischer Erzberg at Eisenerz in Styria is the largest iron ore open-pit mine in Central Europe and the most significant ore deposit in the Alpine region, with extraction documented for more than 1,300 years. Iron ore — principally siderite — has been mined from the mountain since at least the mediaeval period, with a first documentary mention in 1171. Mining was originally conducted by surface working in shallow pits (Pingenbau) and from the sixteenth century through underground adits driven into the mountain.
The Innerberger Hauptgewerkschaft administered the Eisenerz sector of the Erzberg from 1625 until 1881, when the Österreichisch-Alpine Montangesellschaft took over and systematically reorganised the mountain into a terraced open-cast structure. Underground working was closed in 1986. Today the mine operates as a terraced open-cast operation run by VOEST-ALPINE Erzberg GmbH, producing approximately 3.2 million tonnes of iron ore annually.
Visitor access is provided by the "Abenteuer Erzberg" programme, incorporating a show mine ("Schaubergwerk") using the former underground workings, Hauly open-air truck tours across the active pit, and an open-air exhibition at Oswaldirücken.
Iron ore extraction at the Steirischer Erzberg has a history stretching back more than 1,300 years. A possible allusion to the site appears in an inscription once noted in the church of St. Oswald in Eisenerz giving a date of 712 AD for the "discovery" of the ironworks, though this cannot be verified. The Erzberg is first documented in a historical source in 1171. By the fourteenth century the sovereign had issued ordinances regulating ore extraction, pig iron production, and the processing and trade of iron. The mountain was physically divided by the Ebenhöhe, a horizontal boundary at 1,186 metres above sea level, established on 25 July 1524: the upper sector was administered from Vordernberg and the lower from Innerberg, the town later renamed Eisenerz.
In the mediaeval period ore extraction was carried out by the Eisenbauern — smallholding farmers with ore-working rights — in shallow open pits at the surface wherever weathered ore was accessible, a technique known as Pingenbau. As surface deposits were exhausted during the sixteenth century, underground adit working was introduced on imperial orders, with miners following the ore body through 8 to 10 metre high underground chambers. By around 1500 the iron from Eisenerz represented approximately 16 per cent of European export volume by value; by 1550 this had risen to roughly 20 per cent. Ore was smelted using charcoal blast furnaces located in Eisenerz itself and, more extensively, in Vordernberg south of the Präbichl pass. A regulation of 1448 divided the sales territories: northern European markets were supplied from Innerberg, while south-eastern Europe was supplied from Vordernberg.
In 1625, following financial difficulties among the closely interrelated Radmeister families and the onset of the Thirty Years War, the sovereign took control of the Eisenerz sector of the Erzberg, compulsorily consolidating the workings and founding the Innerberger Hauptgewerkschaft, which administered the Eisenerz portion of the mountain through to 1881. During the seventeenth century the Innerberger Hauptgewerkschaft grew to become the largest iron-producing enterprise in the world. In 1720 black powder blasting was introduced at the Erzberg for the first time, transforming the speed of extraction; dynamite followed in 1870, and electric mine detonators were introduced in 1876.
A primitive railway for ore transport was first laid at the Erzberg in 1810; within 21 years a system of several lines had been constructed around the entire mountain. The Stichbahn (branch railway) from Hieflau to Eisenerz opened in 1875. The Erzbergbahn railway from Vordernberg over the Präbichl to Eisenerz became continuously operable from 1891, with the first steam locomotives running over the Präbichl from 1878. From 1899 the first electric locomotive — a 40-horsepower Siemens & Halske machine — was deployed on the Huntslauf, the ore transport system; the Huntslauf was electrified at the end of 1899 and extended to the blast furnaces at Münichtal in 1901.
In 1881 the Österreichisch-Alpine Montangesellschaft (ÖAMG) took over the Erzberg and systematically reorganised the mine, replacing the irregular patchwork of open-cast workings with a uniform terraced structure: by 1910 58 terraces of 12 metres each in height had been laid out across the mountain. Compressed air drilling machines were introduced from 1906, replacing hand boring; the first drill rigs appeared in 1930. In 1873 the railway line from Eisenerz to Hieflau opened.
During the Second World War the German authorities required sharply increased iron ore output, necessitating major investment in plant and equipment. The 12-metre terraces were converted to 24-metre terraces. Up to 5,000 forced labourers, 2,000 prisoners of war, and between 400 and 500 concentration camp prisoners were deployed at the Erzberg between 1943 and the end of the war.
In 1946 the mine resumed normal operations and continued modernisation of plant. In 1951 the first heavy road transport vehicles (Schwerlastkraftwagen) were deployed at the Erzberg, beginning the gradual replacement of the mine railway system. In 1968 wheel loaders were introduced to supplement excavator work in filling the heavy vehicles. In 1973 the ÖAMG merged with the Vereinigte Österreichische Eisen- und Stahlwerke (VÖEST) to form Voest Alpine Montan AG. Following this consolidation, the underground mine at the Erzberg was closed in 1986, and the trackless open-cast haulage system became exclusive. The Erzbergbahn ore transport over the Präbichl was likewise discontinued; the route survives today as a museum railway. The ore loading installation at Eisenerz station was dismantled and a modern rail loading station was built at Krumpental in 1984.
Today the mine is operated by VOEST-ALPINE Erzberg GmbH, a subsidiary of the voestalpine group. Approximately twelve million tonnes of rock are blasted from the mountain each year across its 30 active 24-metre terraces; from this, around 3.2 million tonnes of pure iron ore are recovered and transported by rail to the steel plants at Linz and Donawitz. Estimated reserves at the Erzberg stand at 235 million tonnes of ore, with extraction expected to continue for several further decades. Since 2019 the Montanuniversität Leoben has operated the "Zentrum am Berg" research infrastructure for tunnel construction and tunnel safety at the Erzberg.
Visitor access to the mine is offered under the "Abenteuer Erzberg" brand from May to October. The Schaubergwerk (show mine) uses former underground workings; visitors travel 1.5 kilometres into the mountain on the "Katl" — a converted former crew train — before touring an 800-metre underground circuit with audiovisual presentations and interactive stations. The underground section was closed in 1986. From 1993 a converted heavy transport vehicle was repurposed as a sightseeing vehicle — the Hauly — for open-air tours across the active terraces of the pit; a second Hauly was added in 1996. The Hauly currently operates as a 1,217-horsepower converted heavy vehicle with a viewing platform. The Oswaldirücken open-air exhibition, at 878 metres above sea level, presents historic mining equipment and art installations alongside views of the active open-cast workings.