Waste is a resource that shouldn’t be wasted. Drawing on this assumption, 5 cities joined in the Greencycle project and tested a variety of actions aimed at developing circular economy. To cite but a few, Maribor (SI) and Trento (TN) created loops across industries to reuse waste as much as possible, while Vienne Coindreau (FR) started producing biogas from the sludge as a step toward its 2050 energy neutrality goal. Thanks to the Greencycle toolbox and to the project transnational network, municipalities in the Alpine Space and beyond will find it easier to build their circular economy strategies.