The Opelbad, located on the slope of the Neroberg on the grounds between the former Neroberg Hotel and the Russian Church, was inaugurated on June 16, 1934, after two years of construction. It was built according to the plans of architects Franz Schuster (Vienna), Edmund Fabry (Wiesbaden), and landscape architect Wilhelm Hirsch (Wiesbaden).

Schuster, who at times taught at the Wiesbaden School of Applied Arts, was, like Fabry, committed to Bauhaus architecture. Like a ship floating on the waves of the forest, the terraced Opelbad winds its way down the slope of the Neroberg, with a restaurant serving as the bridge and the railing as the ship’s rail.

The Opelbad was intended primarily as an attraction for spa guests, who were hard to attract in the early 1930s. The city decided in 1931 that it should be a “summer swimming pool” and “serve the spa experience in particular.” In the 1930s, Wiesbaden promoted itself with the slogan that it was a “synthesis of sun, water, air, and forest.” The Opelbad, which is still considered one of the most beautiful swimming pools in Germany today, was an instant success: as early as the first swimming season, 51,000 tourists and 42,075 swimmers were counted. The man after whom it was named, the industrial magnate Wilhelm von Opel, who lived in Wiesbaden, donated 150,000 marks toward its construction, while the city contributed approximately 100,000 marks. Wilhelm von Opel made his donation contingent on the pool being named after him. Due to his ties to the Nazi regime, the local council responsible decided on September 4, 2024, to rename the Opelbad and remove its association with its founder. This was implemented by a resolution of the city council on March 24, 2026.

The Opelbad features a 65-meter-long and 12-meter-wide swimming pool, a diving tower, a slide, and a wading pool for children.

Toward the end of World War II, the pool was closed; after their entry into Wiesbaden on March 28, 1945, the American occupying forces confiscated it. It was not until 1952 that they returned it to the people of Wiesbaden. For a long time, the pool was managed by the spa administration; later, it was managed by the spa operations.

Since 2008, it has been part of the municipal enterprise Mattiaqua, which also includes, among other facilities, the thermal baths in the Aukamm Valley.