Visit of the Idrija Museum in Slovenia: 500 years of Mercury history

Idrija is about an hour drive from Ljubljana and his home to the second largest mercury mine in the World. Come along for a visit of the Idrija Museum which will tell you all about mercury mining…





Mercury and mercury mining isn’t the most common topic for a museum. Admittedly, before going to Idrija, I knew very little about mercury. We are talking here about the chemical element, not the planet, although I don’t know much about the planet either 😉

So you can grasp the depth of my ignorance, let me list the things I knew: mercury can be found in thermometers & barometers, dental amalgams & fluorescent lamps. Mercury is poisonous. That’s it!

Learning a thing or 2 when travelling is always an added bonus so as you can see, visiting the Idrija Museum was a nice addition to our road trip in Slovenia!


Let’s dig into what you can learn when visiting the Idrija Museum.


Mercury & Mercury Mining


Mercury is a very rare chemical element. It is the only metallic element to have a liquid form. Discovered centuries ago, it was used in Chinese & Greek medicine and Egyptians & Romans used it in their cosmetics. Yes, we do know now that it is highly poisonous (for us and for the Earth) but it is still commonly used in mascaras!


Nowadays, mercury has a lot of electronic applications although it is still used, amongst other things, as a preservative in some vaccins (OK I’m not an expert and it seems to be a different form…).

So what about mercury mining?

Mercury is mostly found as deposit in ores. These ores have to be extracted from the earth, crushed and heated. The mercury there after is released as vapor which becomes liquid when cooled off.




Mercury is so dense that other metals float in it. Pretty cool!!


The Gewerkenegg Castle 


The Gewerkenegg Castle or the ‘mine castle’ was built between 1522 and 1533 by the mining company which owned the Idrija mines at the time. It was the mine administration & management center and residence for the mine administrator. Originally it was also used to store mercury and other living necessities for miners.

In the 18th century, the castle was renovated in baroque style. The decorative frescoes you can admire in the courtyard were added then.

Like many other places, the 20th centuries wars affected the castle greatly and it’s only in the 1950’s that the castle began its new life as a museum, music school and as a cultural events venue.

Today, the Gewerkenegg Castle is filled with light. It is warm and welcoming and it makes it difficult to imagine what it might have been like centuries ago.


The Idrija Museum tour: 500 years of mining history


The Idrija museum occupies the 2 main floors of the castle and 3 of the 4 sides. The journey starts with a retrospective of the milestones of the story of Idrija’s mines. Follows the display of all sorts of fossils rocks and minerals from Idrija and from around the World.

In the center of the room, a round vessel contains liquid mercury in which an iron ball is floating. Pretty bizarre!!





Further along, the night watchman is ready to call the miners to the reading by knocking on a wooden rail. Various documents are displayed and maps of the Idrija mines showing the 700 km of tunnels and shafts will attract your attention. It’s not that easy to understand them!



One room of particular interest is the mercury tower, a symbolic entrance to the Idrija’s underground mines. Snapped like a mine shaft, the stairs will take you down below to the treasure! Spoiler alert, the treasure is a plexiglass square filled with mercury drops. Soooo pretty!!


The walls display items used by miners and I loved those lamps.

Probably the most surprising piece was the death clock. A simple wooden board where miners were to put back their numbered token when coming back up from the mine. A way to keep track of who might have been left behind…


In the Idrija Museum, you will also learn about the famous people who made Idrija, how mercury was extracted and how the smelting process evolved.

You will learn how the town grew, how the wood required for the smelting process was transported and how life was organized.



There weren’t many people in the Museum when we visited (4 in total including Mr A and I!) and the display of the Idrija marching band was the closest we got to feeling crowed!!
Idrija is a peaceful and green town today but part of the exhibition takes you back to the Italian and German Occupation period and the organisation of the resistance mouvement.
Toward the end of the exhibition, the Idrija town pays hommage to one of its distinguished citizen, writer France Bevk, by displaying his office and library.


The display and information about mercury are quite fascinating. The museum truly provides comprehensive information in an attractive way and the Gewerkenegg Castle is a beautiful home for such exhibition.

Yet the ugly true of mercury mining isn’t forgotten….

Idrija Lace 


Idrija isn’t famous just for its mercury mines. The bobbin lace that has developed in the Idrija region for centuries as an additional revenue stream for mining families, is also pretty famous.



It is refreshing to be able to admire such exquisite and refine lace pieces and even evening gowns after having been immersed in the mining world!


Just a few more words…


I’m a huge UNESCO World Heritage sites. OK you knew this already!


I’m not a huge fan of industrial related sites. I’m not sure why. My green side might not like to be reminded how much efforts humans have put over decades or sometimes centuries to find more efficient ways to destroy & trash the Earth. It might just be that I’m not that interested in the industrial revolution?!

Really not sure, but I easily admit that I did get a change of heart when we visited the Grimeton Radio Station in Sweden. That was quite interesting and even fascinating.

So, when planning our road trip to Slovenia, I didn’t hesitate to include Idrija on the itinerary. Now, I didn’t plan this well enough and we did not have time to do everything that we should have done there. I guess it means we’ll have to go back but it also means that I can give you some advise 😉 Read on…


The Technical bits: 


When arriving in Idrija, start your visit at the information center, where you will be able to get a lot of information about the region. To plan ahead, visit the official website:

Plan to stay in Indrija or around for more than a day. There is so much to see and do that you won’t regret it.

This is what I would recommend:

  • Visit the Municipal Museum first, to learn about mercury and the mining process.
  • Stop by the Church of the Holy Trinity.
  • Visit Anthony’s Main Road, the oldest part of the mercury mine.
  • Go for a walk along the river. Follow the signs: Rake Water Channel and bring your bathing suit!
  • Continue to the Wild Lake
  • Continue the trail to see one of the water barriers or all 3!

A bit further away, you may find the Franja Partisan Hospital quite interesting.

There are a lot more things to do, but those are my recommendations!

Idrija is part of the Heritage of Mercury UNESCO World Heritage sites (details here) .



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