The City Demonstrator at HFT Stuttgart shows us today the smart city of tomorrow. It offers researchers a visualization environment in which they can vividly and realistically simulate, test and present digital research results. The touch table can be used to simulate and visualize large-scale projects and their impact on urban space. The HoloLens makes it possible to immerse oneself in an augmented reality environment and interact with it. And the KAT Walk in combination with virtual reality goggles makes it possible to enter virtual worlds and move freely within them.