The famous physician Galen already wrote in antiquity: “Water possesses the properties of the rock layers through which it flows.” This principle is also evident in the Feengrotten. Here, there are both highly mineralized healing waters and less mineralized springs that were used as drinking water.

In 1910, a small group of men bravely ventured into the disused mine in search of the origin of these springs. Old mine plans no longer existed, and the former entrances had since been buried. The only way led through a tunnel about one hundred meters long. Under difficult and dangerous conditions, they worked their way step by step into the interior of the mine.

To their great surprise, they discovered the current spring grottoes and the origin of the underground springs. Chemical analyses confirmed the high mineral content and medicinal value of the water. Initially, there were plans to establish a spa at this location. However, the extraordinary beauty of the grottoes convinced Adolf Mützelburg, the founder of the Feengrotten Park, to make the caves accessible to visitors instead. On May 31, 1914, the first guests were able to visit the Feengrotten.

In addition to tourist operations, mineral water from the Feengrotten was also bottled between 1928 and 1964. Under the name “Saalfelder Heilquellen” (Saalfeld Healing Springs), it was distributed throughout Germany. Due to its special composition of phosphorus, arsenic, iron, and sulfate, it was considered an effective healing water and was used, among other things, for gout, gall bladder ailments, nervous disorders, anemia, and metabolic disturbances.

In 1964, the Soviet-German joint-stock company Wismut began exploring for uranium deposits in the vicinity of the Feengrotten. Numerous deep boreholes were drilled for this purpose. However, after the work was completed, the boreholes were not adequately sealed. As a result, the highly mineralized healing water shifted to other rock layers and could no longer be extracted.

In contrast, the less mineralized water from the mine was bottled and sold as spring water under the name “Saalfelder Gralsquelle” (Saalfeld Grail Spring) from 1933 to 2005. When demand exceeded the natural water supply, another deep borehole was drilled in 1939. The former bottling site is now part of the Grottoneum. There, you can still taste the mineral water in its original form – and experience its characteristic iron taste for yourself.

Ochre is a natural pigment that appears pale yellow to yellow-brown depending on its composition. It has been used as a dye for millennia. Ochre occurs in many different forms in nature. Chemically, it is formed by the weathering of iron-bearing rocks and contains large amounts of water-soluble iron oxides.

Following the closure of the mine in 1855, the Saalfeld entrepreneur August Wohlfarth acquired the site in 1867. He dammed the mine water in the drainage gallery and extracted iron ochre from it—without knowing its actual origin. In his factory in Saalfeld, the ochre sludge was dried and processed into color pigments, which were used, among other things, for facade paints.

The company enjoyed moderate success until 1909. However, as the ochre yield continued to decrease, production eventually became unprofitable and was discontinued. This marked the end of the utilization of mineral raw materials from the “Jeremias Glück” mine.

Nevertheless, the emerging ochre sludge remained popular with the local population. Healing properties were attributed to it, and since the 20th century, it has been used with great success to treat various ailments—including rheumatic diseases.