There is evidence that the graduation towers used for producing salt in Bad Münster am Stein already had their current form as far back as 1729. The weakly salty water from the salt spring is delivered to the graduation towers by pumps formerly driven by waterwheels, but now driven by electricity. From the top, the water trickles down in innumerable drops through walls of blackthorn to a collection basin, while the air in the area is enriched with salty material such as iodine, bromine and strontium ions as well as the noble gas radon. By making the water into mist during its trickling through to the collection basin, the water's saltiness is raised. The waterwheels and part of the equipment (rods for transmitting the motion) can still be viewed.