When Count Wilhelm IX of Hessen-Kassel bought the plot of land on the outskirts of Bad Nenndorf, where the sulphur springs bubbled,  he thereby founded the spatown. This was in 1787. Before long the building of the cure facilities started, for the medical value of the sulphur springs had been known for some time.

Die Count of Hessen gave order to erect a lodging house and only at the end of the 18. century Bad Nenndorf belonged to the famous curing baths in the country.

After having been raised to a noble Prince Wilhelm put forward the building of a Residence featuring his social status, the “Schlösschen”. Beside this lodge in  classicistic style the “Landgrafenhaus" and “Haus Kassel” date from the early days of the Health place.
Another important development happened in Bad Nenndorf after becoming “Königlich-Preußisches Heilbad" in 1866. The impressing architectural testimonial is the Great Bathing House, built in 1905/06 on the fringe of the Kurpark.