2022-02-24 00:00:00 In the Aachen underground lies a millennia-old treasure - the thermal springs. This is spring water, which comes from thousands of meters deep, and is therefore very hot, up to 72 ° Celsius. The sources are the reason for the emergence of Aachen. The app "aachen 72 degrees" makes this "buried" wealth visible in the city Aachen and leads to ten selected places that have a cultural-historical and / or geological reference to the thermal water sources or thermal water. Worth knowing, amazing and curious, but especially the invisible and the disappeared is brought to light, conveyed in different depths and can be experienced in a playful way.