Bad Nauheimer Sole

As a spa town Bad Nauheim is well known. However it is not commonly known that Bad Nauheim had a long lasting tradition to produce salt.

Carbonic acid (Carbon dioxide) is discharging in the valley area of Bad Nauheim, in particular in wells, boreholes, but also from the Usa arroyo. In the underground the saline water is charged with carbon dioxide gas. Relief of pressure causes the carbon dioxide gas to escape causing a buoyancy effect. The same effect causes bubbles in mineral water. The saline water could be found along the edge of a fault zone between geological layers of Lower and Middle Devonian.

The salt springs were of particular importance to the development of Bad Nauheim. Celtic settlers used the saline spring water (brine) in Nauheim already in the 5th century BC to produce salt. The salt was made by boiling the brine. To the reduce the need for wood as heating material the salt concentration was increased using evaporation. As in many other areas thorn houses were used in Bad Nauheim for the graduation process. They still shape the city of Bad Nauheim. Sun and wind evaporated water from the dripping brine and the salt concentration increased. The natural salt concentration of the Nauheim brine is 3%. Through the graduation process the concentration was increased to 16%. Finally, the brine was heated in boiling pans until the salt crystallised. In 1959 the salt production was stopped.

The discovery of the medical benefit of the brine and the solute carbon dioxide, initiated the development of Bad Nauheim into an important spa town in the 19th century. The water was successfully used to treat cardiovascular disorders, rheumatic diseases and respiratory illnesses. Many guests came to Bad Nauheim to undergo a cure treatment. Among them were many celebrities including the Austrian Emperor and Empress, the Russian royal family, the composer Richard Strauss and the author Karl May.

To meet the increasing demand for brine for the salt production and the spa new springs needed to be found. Many wells have been drilled. The most famous active wells are the "Große Sprudel (Big Spring) and the Friedrich-Wilhelm-Spring. Both are located in the Sprudelhof. The form the centre of the largest closed Jugenstil (Art Nouveau) construction in Europe. They still supply the adjacent spa with brine. A third well, the Ernst-Ludwig-Spring has been closed. The stand post, which is uphold by 8 seals is still there.

To log this cache, you need to meter the temperature of the “Große Sprudel” fountain. It is the fountain on the east side (direction train station). You should bring a thermometer with you. In case you did not bring one with you there is a backup thermometer close-by available (N 50°22.079 E 008°44.669). I put it behind the rain water pipe.

You must also find the answers to the following three questions. The white boards in the colonnades of the court should help you getting the right answers. Unfortunately, these information boards are available in German only. Friendly people might help you solving this issue.

1) How many springs form the basis of the Bad Nauheim hydrotherapy?
2) Find the warmest spring. What is the designated roman number?
3) How deep is the deepest well (m)?

To get log permission please send an email to the following email address:
Answer1Answer2Answer3@googlemail.com

Assuming the correct answers would be as followed (they are not !!):
1) 9
2) IV
3) 86m

You should send an email to 9IV86@googlemail.com

After receiving the log permission you are free to log.

Please, mention the current temperature of the “Große Sprudel” fountain in your log. Take also a picture of yours with your GPS and your thermometer in front of one of the springs and upload it to your log. Picture upload is not a requirement to log but would be very nice anyway.

If you are interested in further information about salt production in Bad Nauheim you may either follow the public course "Sole und Salz" or participate in a guided tour. It is organised by the tourist information. The book "Die Saline Nauheim" by Roland Scharf is a useful source for home studies. Unfortunately it is only available in German.

Enjoy the Cache!!


Visit also Geocaching Wetterau


These pictures were taken at the clean-up in autumn 2010. On the left picture you can see the sinter (mineral deposition of the sole). The right picture shows the renovated fountain.