In the Taschenwald there is a former brine field, where rock salt was extracted from the Middle Muschelkalk between 1957 and 1993. A total of 40 boreholes were created, each with two sections approximately 1,000 m long, into which pre-purified Neckar water was introduced. This was enriched with the salt and pumped out as concentrated brine. The highest
extraction rate was up to 150 m³/h of brine, which was pumped via a pipeline to the alkali and soda factory in Heilbronn. In 1964, leaching caused cover layers to collapse, resulting in a deep collapse of now over 100 m, which is sealed by marginal landslides made of loess/loess clay material. This maintains a permanent
water surface that is fed by groundwater.
Source: LGRB - Geotope profile