Seeheim-Jugenheim is a municipality in the Darmstadt-Dieburg district in Hesse, Germany. It has a population of approximately 17,000. The municipality was formed on 1 January 1977 through the unification of the previously separate municipalities of Seeheim and Jugenheim. Until 1 January 1978 the municipality was known as Seeheim; after that it be…Seeheim-Jugenheim is a municipality in the Darmstadt-Dieburg district in Hesse, Germany. It has a population of approximately 17,000. The municipality was formed on 1 January 1977 through the unification of the previously separate municipalities of Seeheim and Jugenheim. Until 1 January 1978 the municipality was known as Seeheim; after that it became known as Seeheim-Jugenheim.