The water of the Claudius Therme

The history of Cologne's thermal water

In contrast to the old bathing resorts such as Aachen, Karlsbad or Baden-Baden, which date back to Roman times and which are steeped in tradition, "the spa town of Cologne" was only founded in the 20th century. Only in 1912 was the CO2 and chloride-rich mineral water found at a depth of 70 m in the Stammheim district of Cologne during a search for drinking water. This first well, the Engelbertus well, was in use until 1955. In 1931, the Lord Mayor at the time, Konrad Adenauer, ordered the 251 m deep "Messebrunnen I" ("trade fair spring I") to be drilled at the site of the trade fair in Deutz. This is where state-accredited mineral water was supplied from a non-commercial mineral spring. A further 120 m deep "Messebrunnen II" drilled close to this well remained insignificant. Within 30 years, the massive corrosive effect of the chloride water containing CO2 made the "Messebrunnen I" unusable. That is why, in 1961 and 1962, the 364 m deep "Messebrunnen III" was drilled, from which up to 200 m³/h of thermal CO2-rich, sodium chloride water can be pumped every day. In order to achieve a higher temperature of the water supplied for bathing purposes, Messebrunnen IV (1027 m deep) was sunk with a great deal of technical effort between 1974 and 1976. The sodium-chloride water is pumped out of the borehole lined with steel pipes at a temperature of 28.5 ° C. Messebrunnen III as well as Messebrunnen IV are also available to the Claudius Therme. This ensures sufficient output with consistent quality.


The thermal mineral water pumped in the Claudius Therme has come a long way: rainwater trickles down in the region of the Bergisches Land and flows down the slope of Devonian limestone and dolomite (approx. 350 m years old) to the west, in the direction of Cologne. On the way there, it heats up due to the flow of heat from the interior of the Earth and becomes thermal water. At great depths (300 to 1,500 m), this warm water mixes with mineral water containing chloride. It is the free carbon dioxide that exists here that is ultimately responsible for the "thermal sodium-chloride acidulous mineral water" of the Claudius Therme. The carbon dioxide, as a so-called "gas lift", gives the water a natural tendency to rise so that it can be easily transported through Messebrunnen III and IV built from 1961 to 1962 and from 1974 to 1976 respectively without any major difficulty. Cologne forms the northernmost extension of the "carbon dioxide line" that was created by volcanic activity and which starts at Laacher Lake and stretches all the way across Bad Breisig, Bad Honnef und Bad Godesberg. Against the background of the middle Rhine volcanic activity in the geological past, it is the special geological structure of the Rhine Basin and the wealth of precipitation of the low mountain region of the Bergisches Land that form the basis for the unique thermal water of Cologne. This water originates in a natural way and can, in view of its high recharge rate and constant level of quality, be extracted without adversely affecting the geohydraulic conditions.

The healing water

The thermal mineral water of the Claudius Therme, the "thermal sodium-chloride acidulous mineral water" of the Claudius Therme, is wonderfully suitable for bathing in particular. Moreover, it can also be drunk or inhaled. As a drinking cure, it eases gastro-intestinal problems; as a bathing cure, it aids rheumatic complaints and diseases of the intervertebral discs or joints. It has a positive effect on hypertension, circulatory problems and disorders caused by stress; it activates enzymes and stabilises bone structure. The healthy spa effect of the unique thermal mineral water of the Claudius Therme has been accredited by the state.

This unusual water ...

  • is effective like the thermal water of state-accredited spa resorts
  • is of benefit to the circulation, joints, the intestines and the heart
  • is pure and as nature intended
  • has been tested by the Institut Fresenius
  • has flowed through limestone and dolomite for 39,000 years
  • is naturally enriched with minerals
  • is naturally carbonated
  • and has been freshly extracted from deep layers of rock from the company's own well.

Bathing in this thermal mineral water and visiting the saunas and steam baths promotes health from a medical point of view, which is why it is recommendable for everyone.

One's physical well-being and health are markedly improved. When combined with the relaxing atmosphere of the bathing facilities and the view of the Rheinpark in particular, a visit has an excellent recuperative effect even after only a few hours.

Due to the therapeutic effect of the healing water, medical treatments are also part of the services offered by the Claudius Therme: physiotherapy pools, physiotherapy, classic and special massages, lymphatic drainage and fango mud treatments. These services are not included in the entrance fee, but they are available on presentation of a doctor's prescription or separate payment. For more information on these services, see Beauty & Wellness or Physiotherapy or call +49 (0)221-981 4420.

Chemical analysis:

On average, 1 litre or 1 kg of water from the "Messebrunnen III" well in Cologne contains the following:


  • sodium 3,757.00 mg
  • potassium 89.90 mg
  • ammonium 5.58 mg
  • magnesium 318.60 mg
  • calcium 608.10
  • manganese (II) 0.69 mg
  • iron 4.25 mg
  • total 4,783.82 mg


  • chloride ion 5,902.00 mg
  • sulphate 754.80 mg
  • hydrogen carbonate 2,471.00 mg
  • total 9,127.80 mg

Undissociated components:

  • silicic acid 16.60 mg

Gaseous components:

  • free carbon dioxide 1,538.00 mg


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