No matter if graffiti writers, architects, skaters, homeless people or investors: They all have their unique view on the city, they all perceive of a very special kind of space that the other groups are blind to from their own functional perspectives. Nevertheless, it have been homeless people and artists in particular who have entered into that special negotiation with urban space which the situationists have come to call “dérive”: drifting and roaming around aimlessly. Apart from those spaces and institutions exclusively dedicated to production, consumption or recreation, the city harbours countless interspaces, interstices, where things unnoticed, forgotten or unfinished open up new connections and allow for new relations – spaces one only needs to experience in order to make them become a reality. Javier Abarca tried to reach out to the “excluded” realities of the city and guided the participants of his expeditions to all those hidden spaces under bridges, along railways, on vacant lots and in tunnels. It is here where nothing is provided, nothing is produced that everything becomes determinable. Sous les pavés, la plage. Under the pavement, the situationists declared, the beach lay.