Perched 1,036 meters high on the Hornisgrinde, Mummelsee is a dark, acidic “kar” lake that serves as the primary gateway to the kingdom of the Mümmlein (Water Nymphs) and their King. Unlike typical river spirits, the Nixies of Mummelsee are said to reside in a magnificent crystal palace hidden beneath the lake’s impenetrable black surface, rising only at night to dance in the moonlight. Local folklore, spanning centuries, warns that the lake is “bottomless”—a belief reinforced by the water’s lack of visible life due to its high acidity.Throwing stones into the water will provoke the King of the Lake to conjure violent, localized thunderstorms. This specific site gained literary immortality through Eduard Mörike’s 1829 ballad Die Geister am Mummelsee, which depicts the lake as a portal where the line between the living and the spirit world dissolves in the sudden, thick mountain mists.

Modern-day activity at the site is frequent, with hikers and “legend hunters” documenting strange, rhythmic ripples on the lake’s surface during perfectly still conditions—disturbances locals attribute to the Nixies returning to the depths. In 2024 and early 2025, travel vlogs and regional paranormal forums have highlighted the “Bronze Nixe” statue as a focal point for modern sightings, with some visitors claiming to capture “transparent figures” in the background of their photos during the twilight hours. The atmosphere of the site is defined by the “Mummelsee-Geister” (ghosts), who are believed to be the spirits of those lured into the depths by the Nixies’ song.