The brine well "Westernkottener Warte" was developed in 1845. The depth of the borehole is 78 meters.
It was discovered by chance at that time, because actually rock salt was searched for. Instead of finding rock salt, this brine spring was discovered by surprise and shot out of the borehole in a large fountain.
Until 1949, the very productive brine spring was mainly used for salt production and also for healing purposes. With the cessation of salt production in Westernkotten in 1949 and the founding of Solbad Westernkotten GmbH in the following year 1950, the transformation of the former saline village of Westernkotten finally took place. Since then, the brine has been used exclusively for bathing and for health-promoting and health-maintaining purposes at the two Gradierwerks.