Gradierwerk Bad Dürkheim

These are wooden structures from which salty water trickles down (often part of a salinarium). Originally, graduation towers were used to extract salt: salty water (brine) from springs was passed over brushwood walls (usually blackthorn). Evaporation increased the salt content and the salt could then be extracted more easily from the brine. Today, graduation towers are mainly used for health purposes: A fine salt mist, similar to sea air, is created as the brine trickles down, which can moisten the respiratory tract.