The River Danube originates below the church hill, directly adjacent to the princely palace. It originally flowed openly passed the palace, joining with the Brigach und Breg about two kilometres to the east to form a single large river. Marshland with numerous other springs and water courses was located beyond the Brigach.

The water from the Danube Spring now flows in the subterranean canal directly into the Brigach. The site of the marshland has been replaced by the princely park with its ponds and canals.

The Danube Spring has been famed since the time of the Romans. The military commander and future emperor Tiberius visited the site in the year 15 BC and Emperor Maximilian held a ceremonious court here in 1499. The last German Kaiser, Emperor Wilhelm II, likewise visited the Danube Spring on several occasions between 1900 and 1913.

Prince Karl Egon III had the present rim surrounding the Danube Spring built in 1875. The sculpture at the centre depicts “Mother Baar” pointing the young Danube on its 2840 kilometre long journey from its source at Donaueschingen to the Black Sea.