In essence, walking is about being mobile on the face of the planet. Yet, it is also about knowing and understanding your environment so you can navigate within it. When you meander through the streets of neighbourhoods that were formerly foreign to you, you develop a new relationship with your city. When you wander around in a landscape at your own pace and measure the surface of the Earth one step at a time, you start noticing things that you could not have seen from a car. Walking allows you to get to know your territory from a different perspective. Therefore, it is also projective. This is the philosophy of Metropolitan Trails, an interdisciplinary network of public and private actors focusing on creating public trails in metropolises across Europe.