Raffelberg Manor

The earliest mention of Raffelberg dates back to 1486, when Johann, Count of Limburg and Lord of Broich, leased the property, consisting of a house and farm, to the couple Diderich up dem Grimberge and Elsken for life. In 1855, a saline thermal spring was discovered by miners from the Alstaden colliery. After the discovery of an even larger spring in 1884, a brine bath was built on the colliery grounds. When the re-municipalization of Alstaden from Mülheim to Oberhausen was pending, it was decided to relocate the brine bath to Speldorf. In 1908, the city of Mülheim founded the Solbad Raffelberg stock corporation with local companies and acquired the estate, which had housed a children's sanatorium since 1888.