Active Edge is a radical strategy that specifically addresses the unitary dimension (spatial and biological) characterizing every landfill, retracing it in order to visualize and nurture its presence. Active Edge understands such residual places as potential autopoietic systems: urban organisms able to constantly (re)produce their own components and relative network of processes. Active Edge focuses on the landfills border to generate a space of friction (denser exchange), which filters external energies (people, water, watts) through a self-contained and artificial landscape. Active Edge programs the complex of liminal activities in terms of dichotomies: research/waste collection (west), leisure/water treatment (south), leisure/landscape (north and east). Active Edge moulds three inner landscapes to control planting and stormwater while implementing the use of the edge: cultivation-composting (west), education (baricenter), reforestation (east). Active Edge is both programmatic cause and visible effect of recognizing the landfill as autopoietic machine sitting at the bottom of all our cities: it wont be possible to ignore it, it would be absurd not to learn from it.