Gradierwerk Bad Salzungen, Graduation tower in Bad Salzungen, Germany.

Gradierwerk Bad Salzungen is a tall wooden structure that stretches across the spa park, filled with blackthorn wood through which salt water trickles continuously. The construction creates an environment where the air becomes enriched with minerals as water cascades down past the wood while visitors walk beneath or nearby.

The first graduation house in Salzungen was built in 1590; by 1800, 24 stood on both banks of the Werra for salt extraction. When the spa opened around 1800, all but the eastern wing were demolished and the remaining structure was turned to therapeutic use. The eastern hall dates from 1796–1797, the western inhalation hall from 1901; both were rebuilt and reopened on 8 July 2023.

The graduation tower is run as part of the Solewelt Bad Salzungen spa, and the western hall built in 1901 is used for inhalation. The drinking hall added in 1906 now doubles as the town's wedding room, so civil ceremonies take place inside the complex.

The graduation halls stand in the spa park on the Werra, with the timber-framed Mittelbau linking the two 80-metre halls; the entrance to the Solewelt is through this Mittelbau. The complex was rebuilt by June 2023 and reopened on 8 July 2023, so the halls and graduation garden are newly constructed. The Trinkhalle is also used by the town as a wedding room, so it may be occupied during ceremonies.

A model of the Bad Salzungen graduation tower stands in the mini-a-thür leisure park in Ruhla, and the town also uses the complex's drinking hall as a wedding room. The two graduation halls were demolished from January 2021 and rebuilt, reopening on 8 July 2023 with Thuringia's minister-president Bodo Ramelow present.