The "dark giants" are striking features in the cityscape. Cool, slightly salty air blows around the large facilities. If you breathe in near them, you will immediately feel a pleasant effect on your respiratory system. But how do the graduation buildings actually work?
The graduation buildings were once used to extract salt. They date back to the 18th century, a time when the Nauheim saltworks was one of the most modern salt factories in Europe. The process is the same then as it is today: the salty water (brine) from the spring is pumped to the top of the graduation buildings. There it slowly flows down the walls made of blackthorn bundles that are up to ten meters high. The wind and sun cause some of the water to evaporate and the salt content increases. The fine salty droplets that are created in the evaporation process and blown away by the wind are then perceived as a fresh sea breeze.
Due to the realization that the salt crystals in the air (aerosols) have a positive effect on our health, the five remaining graduation buildings in Bad Nauheim were given their current purpose as open-air inhalators.