Next to the Delft water tower is the associated pump house with underground clean water cellar, which was used at the time to store two million liters of water. This building from 1918-1919 is located on the grounds of the former municipal cemetery (1829-1874), the current Kalverbos, and is part of the water tower complex and the protected cityscape of Delft. The impressive space was renovated in 2022 to a design by DP6 architecture studio and currently houses RADIUS, a center for contemporary art and ecology.