Idrija Mercury Mine Listed on UNESCO Heritage List

July 2012

Beautiful mercury drops.

On 2 July, 2012 in Saint Petersburg, UNESCO's World Heritage Committee decided to include Idrija's mercury mine along with the mine in Spain's Almaden on its world heritage list. The join bid of Slovenia and Spain focused on the technical heritage connected to the mines in Idrija and Almaden, where two of the world's biggest mercury mines were active until recently.

Photo: Primož Lavre

In recent years, Slovenia has invested much greater efforts in promoting the most outstanding examples of our heritage. Since Slovenia gained independence in 1991, there have been quite a few attempts at inclusion on the World Heritage List: first off, Kras as a specific cultural landscape, then Fužinske planine (the iron foundry highlands) above Bohinj as a specific agricultural cultivation culture, then the industrial town of Idrija and, some time later, Franja hospital, where several hundred injured partisans found shelter during the Second World War. None of the above proposals for nomination, except the pile-dwellings proposal prepared together with Switzerland, was successful, mainly owing to our lack of sufficient maintenance and promotion of these properties.

However, these failed candidacies nevertheless helped our experts master the criteria that need to be considered when submitting a nomination proposal for inscription. It was essential to learn that our own admiration of a site is not the most important aspect, but rather the outstanding value of the monument within the context of the development of our civilisation.

The mercury mine in Idrija discovered in 1492

Franciska’s Shaft Building. Photo Anton Zelenc, Idrija Municipal Museum

The Idrija Mercury Mine complex, which, from its very beginnings, was considered one of the best of its kind – along with a similar mine in the Spanish Almadén – fully met these criteria.

Mercury is a very toxic liquid metal which is almost no longer used since it is difficult to degrade and remove, yet it has played an extremely important role in the history of human technological development. Thermometers, various sensors, thermal switches and valves, incandescent lamps and luminaries in general are inventions that would not have existed without this metal, which has been replaced by other, less toxic substances only in recent years. Both mines have developed important specific features in the extraction of this metal, because the miners were well aware of the threat posed by the substance they were dealing with. The special devices for the collection and cleaning of mercury developed in Spain and in our country are a true wonder of technical ingenuity and skill, given that the history of mining goes back several centuries and forms the basis on which the towns of Almadén and Idrija were built.

The mine in Idrija was closed down in around 1980 through a gradual process which set an example for the sensible and respectable conclusion of an industrial activity which deserves the utmost respect of history and the environment.

Kamsti water pumping wheel at Joseph’s Shaft. Photo Anton Zelenc, Idrija Municipal Museum

Slovenia, Spain and Mexico (which also has an important mercury mine) had submitted their nomination proposals to be considered for inclusion in UNESCO World Heritage List years ago, but the committee responsible repeatedly requested that the proposals submitted be supplemented with new facts and data, in accordance with very strict criteria. This was also the reason why Mexico abandoned its pursuit two years ago, whereas the other two countries have persisted in supplementing their proposals. At the beginning of May, the International Council on Monuments and Sites (ICOMOS) session, which was held in Brussels, finally yielded some good news: our nomination file was given a positive report and expert recommendation for inscription; this, however, was ultimately decided by the responsible committee in Saint Petersburg  on 2 July 2012.

Franciska’s Shaft Building. Photo Anton Zelenc, Idrija Municipal Museum

Inclusion in the World Heritage List will certainly open up a whole new chapter for Idrija: regardless of the fact that, even today, Slovenia is investing considerable assets into the maintenance of the mine as a technical monument, the opportunities for obtaining additional funds  will be enhanced, and the mine will attract considerably more visitors. At the same time, our national pride swells since the recognition of the outstanding value of the Idrija Mine corroborates the good reputation of Slovenia's industrial prowess and diligent work, which is also pursued in other fields of industry that Slovenians have mastered.

Text by Jože Osterman, Sinfo, June 2012 

Photo:  Anton Zelenc, photograph collection of the Idrija Municipal Museum