Climate protection and sustainability are central to the urban development of Heidelberg. All the city’s municipal buildings have been constructed or retrofitted to the highest efficiency standards. Over the last seven years apartments for nearly 4,000 people were constructed in a net-zero district. The district heating system used by the local utilities is one of the greenest in Germany. And trams, charging stations for electric vehicles and cycling paths are continuously improved. However, if you want to turn this positive spirit from the last few decades into a something enduring you need to have the broad support of the citizens. Therefore, for many years the municipal administration of Heidelberg has carried out a number of projects to raise awareness of sustainability, starting with the youngest citizens – in childcare centres.