Raffelberg Manor

In 1486, Johann Graf zu Limburg and Herr zu Broich leased Raffelberg, house and farm, for life to the married couple Diderich up dem Grimberge and Elsken.

In 1855, miners from the Alstaden colliery, while sinking a shaft, discovered a 26°C warm, saline spring – relics of a primeval sea. The iodine-rich brine quickly became popular among the miners. They built tubs on site and bathed before their shifts. When a significantly larger spring was finally discovered in 1884, a brine bath was built on the colliery grounds shortly thereafter.

When plans became concrete to reassign Alstaden from Mülheim to Oberhausen, it was decided to relocate the brine bath to Speldorf. The city of Mülheim, together with local companies, founded the joint-stock company Solbad Raffelberg and purchased the 30 Morgen (75,000 m²) Raffelberg estate on April 16, 1908, where a children's sanatorium had been located since 1888.

After a construction period of 13 months, bathing operations opened under the protection of the goddess Hygieia on May 15, 1909. The brine was pumped through a 2.5-kilometer pipeline from the colliery to Speldorf. The design of the entrance pavilion was undertaken by architects Arthur Pfeifer and Hans Grossmann, while Mülheim building director Karl Helbing is named for the other buildings. Approximately 37,000 m² of forest were cleared for the Raffelberg spa park, designed by landscape architect Walter von Engelhardt. On December 31, 1911, the large spa hall with 800 seats was opened.

When the Alstaden colliery closed on March 31, 1973, and the brine supply ceased, artificial brine was initially used. However, as this was not well received, natural brine was brought in by tanker from the Concordia colliery in Oberhausen.

Due to declining treatment numbers, the brine bath was closed in 1992.

Since 1981, the Theater an der Ruhr, founded by director Roberto Ciulli, has been located in the old spa hall.

Today, an architectural office and a restaurant are also located in the buildings.

Nearby are the Raffelberg hydropower plant, lock, and weir, the Mülheim Racing Club's racecourse, the Ruhr shipping canal, and the Kaiserberg motorway interchange. The old brine bath is a point of interest on the Route of Industrial Heritage (Theme Route 12 - History and Present of the Ruhr).