Radon Spa in Jáchymov

In this post, I am going to focus on radioactive waters within spas – or at least, specifically one spa.

Spas as treatment centres have a very long history and mineral waters have long been touted for their medicinal properties without a full understanding of how it actually worked. During the early twentieth century, many spas throughout the world proudly proclaimed that their waters were radioactive.

Today we are going to look at the Radon Spa in Jáchymov (St Joachimsthal) in the Czech Republic (Bohemia). For consistency, as you can still visit it today, I am going to use the modern name of Jáchymov throughout this post.

Jáchymov (other than it’s an area of outstanding beauty and some excellent ski resorts nearby) has two main natural resources – mines and water. And both of these proved incredibly important in radioactive history.

The mine in Jáchymov, known as the Svornost Mine, has been in operation since 1518 and over its history has been mined for silver, arsenic, zinc and (crucially) uranium ore[1].

In 1864, as part of a drive to deepen the shaft, miners accidentally broke through the Spring Štěpa [2] and flooded the lower levels of the mine with water. Because of the high predicted cost of draining this, it was decided to simply close that area and continue digging for uranium ore in another part of the mine.

After all why wouldn’t they?

We now know (and this is a brutal summary of thousands and thousands of hours of scientific discovery by the best minds that have ever lived), that there are three naturally occurring isotopes of uranium – and all of them are radioactive. Any uranium deposit will contain traces of uranium’s radioactive decay products which include (but not limited to – after all the most common isotope, uranium-238, goes through 17 changes before stabilising as a non-radioactive form of lead) thorium, radium, polonium, lead, and radon which is a radioactive gas.

In its undisturbed state radon (which further decays into a series of short-lived radioactive substances all of which emit alpha particles) would be trapped in the rocks. However, it can get out due to human disturbance – in this case, mining – or through cracks in the rocks emerging either on the surface or into the water.

After Radon was discovered in 1900 and specifically discovered in natural waters in 1903 the resulting therapeutic applications by physicians such as Edmund von Neusser did not go unnoticed in Jáchymov. After a visit from Von Neusser a local physician, named Leopold Gottlieb, realised the potential of the nearby mines as a source of radon.

So, this enterprising doctor set up the world’s first purpose-built radon spa – The Experimental Spa Institute (Versuch-Heilbadanstalt)- a very grand title for what was actually two wooden tubs in Dr Gottlieb’s office which was in the house of a baker in the town’s main square (No 282 if we want to be accurate).

Gottlieb, not concerning himself with such petty concerns, concentrated on building up the business which used radon water to treat rheumatism, gout and spinal cord disease. And he was assisted in this enterprise by a retired miner, Josef Prenning, known locally as Donnerkeil or “thunderbolt”, who supplied the Institute with its water. Donnerkeil, presumably living up to his name, bought the water all the way down from the mine – a distance of around 5km- in a 30-litre wooden hod [3].A few years later, you will be relieved to know, our strong hero was given a break (or he may have died history doesn’t say) and the water was brought down to the town in a horse-drawn cart.

And the combined efforts of Prenning (who probably should get more credit than he does) and Gottlieb saw the business increasing from 30 patients in 1906 to 228 in 1908 [4]. Not only does the increase in numbers indicate that the treatments were successful but Gottlieb tells us they were, in a report listing 105 patients of his patients he claimed that 25 were completely cured and 50% improved [5].

This success rate was not to be sniffed at a time of such uncertain health and even more uncertain treatment rates.

We also can tell that business was doing well because the Austrian Government decided to get in on it. Having built a radium factory in the town in 1907 [6] the Ministry of Public Works now declared that they were opening a state run spa [Harvie, 64] and the Spa Institute for Radium Therapy (Kuranstalt für Radiumtherapie) was duly opened in October 1911 [7] offering baths, inhalation, and drinking rooms.

One service that wasn’t provided was accommodation and this gap in the market was corrected by the magnificent Radium Palace Hotel, which opened in May 1912. Known as the Radium Kurhaus or Radium Kurhotel it offered 350 rooms, 85 bathrooms and the latest in modern conveniences and radium treatments including its own Baths, Drinking Cures and an Emanatorium (Inhalation) Room.

With the quality of the accommodation and the thoroughness of the treatment, Jáchymov continued to grow as a spa town increasing the number of patients it saw in a year by huge numbers. Soon other hotels were being built in the area causing frustration (and a loss of potential income) to the state so they ended up buying a hotel themselves.


Emanation was a popular treatment that utilised radon gas. In Jáchymov emanation could be taken in two ways – in a public radium inhalation room or in a bath.

A diagram, from Radiumkuranstalten und Radiumkurorte in geologischer, biologischer und klimatischer Beziehung by Fritz Dautwitz shows the setup of one of the radium inhalation rooms. Below ground, you can see the radon apparatus and the solid lines (on the left) show the air tubes from the radon rooms back to the gas exchange tank and the dotted lines (on the right) represent the air tubes from the gas tank to the room which is shown as lavishly furnished.

This is very reminiscent to one outlined in The New York Times in 1911 which describes the “Afternoon Radium Cure – the latest fad in Paris Society”, a treatment held in the drawing room of a Dr Fumesan. In this establishment the patients in their “voluntarily imprisonment” while away the hours (2 are recommended) playing bridge, reading, and taking tea whilst radium impregnated air is circulated all around them. This complimentary puff piece for Dr Fumesan’s unnamed establishment concludes that it is: “already the talk of Paris, and it is astonishing how many society women have suddenly discovered that they are suffering from rheumatism in order not to miss the 3 to 5 o’clock Radium Tea.”

Radium Bath with Inhalation

If you preferred your inhalation with your clothes off then The Radium Palace could also fulfil this in one of their 24 (semi-private) bathing cubicles. This particular bath tub was completely covered except for three holes – one for the air tube, one for the air cooler and one for the patient’s head – ensuring the most efficient inhalation method of the radium impregnated water.


And when I went, earlier this year, the treatment was still the same (minus the rather fetching face tube)

Yes, the Radium Palace and the State Spa – now named the Agricola Spa Centre – are still in existence and still, after lots of refurbishment, practising the same treatments. The treatment I had was the Radon bath with a dry wrap which cost 630 CZK (around 20GBP) for a 20-minute bath and 10 minutes quiet lie down.

The water is still brought directly to the hotel from the Svornost Mine (albeit by a complex system of pumps rather than by horse) and is said to “improve the quality of life of the ill, relieves their pain, revitalizes, and restores health.”


What did I think of it? Watch the video to see my excited little face.

References and Further Reading

The Daily Mail 26th May 1927
New York Times 10th December 1911
Radium Palace Marketing Materials 2016

Marjorie C Malley, Radioactivity: A History of a Mysterious Science (Oxford: Oxford University Press, 2011)[6] Page 162

Diana Řeháčková, Jáchymovské radiové lázně (Diana Řeháčková, 2013)[2] Page 14[4] Page 18[5] Page 16[7] Page 18[8] Page 32[9] Page 34

Paul Voosen,  The Stir of Waters: Radiation, Risk and the Radon Spa of Jachmov (Amazon Digital Services, 2011)[1] Page 2[3] Page 3

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