The Svornost mining pit represents an integral part of the Jáchymov spa. This is the place where the radon waters are collected and then piped to the spa-facilities down town.
The Svornost pit, established almost in the same time as the town itself (in 1518), carries its present name, meaning concord (Einigkeit in German), since 1530. It is the oldest mining pit still in operation not only in Czech Republic but perhaps also in entire Europe.
During 16th century the Svornost pit was used for silver mining. Since the middle of the nineteenth century uranium ore became the main resource being mined here. The boom of uranium mining started after 1945 and lasted until 1962 when the mining activities were gradually terminated because there was no uranium left there. In the beginning of 20th century some underground water springs containing radon were discovered and the water showed a positive effect on healing wounds and seemed to improve certain medical conditions. Based on this discovery, the first radon spa-house was established in 1906 in the house No. 282, consisting of two bathtubs. Water from the so-called „Štěpové Springs„ collected on the Daniel floor of the Rovnost mining pit was used for the bath treatment there. At first the water was transported down to the spa-house in buckets or by horses. Since 1908 the water was brought down by a pipeline to the bath cabins made in a former uranium processing plant,and since 1911 to bath tubs in a newly built Spa Building (Lázeňská budova). However the capacity of the Štěpové Springs became insufficient by the twenties of last century. A new source was found and named in memory of Marie Curie´s visit in 1925 after her. In 1960 the C1 Spring and in 1962 the Běhounek Spring were discovered.
During the past years, extensive restorations of the Josef Pit (1983-87) and the Svornost Pit (1992-96) have been carried out. In year 2000 a new spring, called Agricola, was drilled. Recently there are 4 springs being used on the 12th floor of the Svornost mine in the depth of 500 meters under the surface. They are as follows:
Water from these springs is collected into the basin on the 12th floor and from there it is pumped about 400 m higher to the collecting pool on the Barbora floor. The water is then flowing from this basin to the Daniel floor and from there it is distributed by pipelines in the overall length of 3,000 meters to the individual spa-facilities. To provide the best quality of the radon water 2,700 meters of new pipe were laid under the ground in 2001.