The Drei-Lilien-Quelle is the confluence of thermal water from the shallow shaft wells in the area of the Schwarzer Bock Hotel, namely the Goldene Kette, Weiße Lilien and Vier Jahreszeiten bathhouses and the municipal brewing fountain on Kleine Webergasse (today An der Drei-Lilien-Quelle). Its water was later divided between the hotels Vier Jahreszeiten (34.6 %), Schwarzer Bock (25 %), Zu den Weißen Lilien (15.7 %) and the city of Wiesbaden (24.7 %).

After the four fountains were merged and the vault, which was beautifully lined with colored majolica tiles in Art Nouveau style, was completed in 1905. The setting and vault room were neglected for a long time, but have since been renovated, mainly with donations, and reopened to the public in August 2011.