Gradierwerk, Bad Wilsnack

A graduation tower is a structure used in the production of salt which removes water from a saline solution by evaporation, increasing its concentration of mineral salts. The tower consists of a wooden wall-like frame stuffed with bundles of brushwood which have to be changed about every 5 to 10 years as they become encrusted with mineral deposits over time. The salt water runs down the tower and partly evaporates; at the same time some minerals from the solution are left behind on the brushwood twigs. ()