The building is wholly artificial and was built for the king as an illustration of the First Act of Wagner's "Tannhäuser". Ludwig liked to be rowed over the lake in his golden swan-boat but at the same time he wanted his own blue grotto of Capri. Therefore, 24 dynamos had been installed and so already in the time of Ludwig II it was possible to illuminate the grotto in changing colours. The grotto is closed to visitors through 2024 for reconstruction and restoration.