It replaced a well from the beginning of the 17th century, one of four such wells in the square. This Baroque sculpture in sandstone, whose subject matter harks back to the Greek mythology (it depicts the abduction of Proserpine by the ruler of the underworld), was made by Augustine Schöps. The four reliefs on the sides of the cistern represent the elements: fire, wind, water and earth, and next to them is the city's coat of arms. The sculpture is an outstanding piece of art, completely unrelated to the architecture that surrounds it. It was renovated in the 90's.