Where, if not at Seestadt (literally "Lake City" in English), is it advisable to think about how to handle rainwater and improve the microclimate? It is therefore not surprising that here, too, a field of experimentation is being opened up for the city of tomorrow. The Schwammstadt ("Sponge City") principle ensures that trees are supplied with sufficient water even in very hot weather and long periods of drought. This is made possible by an ingenious system in which sufficient ballast is created underneath the paved surfaces in the road space to store rainwater. Since the application of this project has not yet been tested under the climatic and meteorological conditions in the northeast of Vienna, the implementation of this project represents an experiment that will be closely monitored and evaluated.