This 12-metre-tall tower is a joint project by architect-theorist Spuybroek and artist Serafijn. An interactive artwork, it is to reflect the daily mood in Doetinchem. Armed with a website, a group of residents relays these day-to-day feelings which are then visualized in colours emitted by LEDs: green for hate, blue for happiness, red for love and yellow for fear. The D-Tower is assembled from polystyrene blocks over which latex has been stretched and a finish of glass-reinforced epoxy resin applied. Its blob-like form is inspired by a beating heart. The final form and structure were fixed by suspending a model upside-down. The D-Tower is blue most of the time; evidently, Doetinchem is by and large a happy place.