The Olga Cave is the longest tuff cave in Germany and a geological juwel. Its appearance is completely different from the other show caves in the Swabian Alb. The cave walls consist of beige-yellowish rock with many cavities that form bulbous shapes. Unlike the numerous karst caves in the Alb, the Olga Cave was not formed by the dissolution of limestone, but by the formation of new lime tufa in which a cavity was preserved. These are called primary caves, which are very rare.
Special feature: Primary cave
The formation of lime tufa is the opposite process to lime dissolution. During the formation of karst caves, water dissolves the lime and transports it away. In the formation of lime tufa, the dissolved lime in the water precipitates again and is deposited as rock. Porous bulbous surface forms, so-called "cauliflower sinter", are typical.