The "dark giants" are striking features in the cityscape. Cool, slightly salty air blows around the large systems. When you breathe in near them, you immediately feel a pleasant effect on the airways. But how do the graduation buildings actually work?
The graduation buildings were once used for salt extraction. They date from the 18th century, a time when the Nauheimer Saline was one of the most modern salt factories in Europe. Then as now, the process is the same: The salty water (brine) from the spring is pumped up to the top of the graduation buildings. There it slowly flows down the walls of blackthorn bundles, which are up to ten meters high. Due to the wind and sun, part of the water evaporates and the salt content increases. The fine salty droplets that arise in the evaporation process and are blown away by the wind are then perceived as a fresh sea breeze.
As a result of the knowledge 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 inhalers.