In the selection process of the Real-word Lab's location, special emphasis was placed on stakeholder participation. With the help of our local academic partner, the Center for Sustainable Development Studies (CIEDES) of the University of Costa Rica, we selected the river Quebrada Seca as an appropriate investigation area. A workshop with the 5 municipalities sharing the watershed was carried out and the project’s idea to co-design and implement Nature-based Solutions prototypes to empirically study their impact in a Real-world Lab at the neighbourhood scale was presented and discussed. Following the workshop, the municipalities were asked to propose possible experimental sites within their administrative areas with prototype placements of Nature-based Solutions. From the proposals received, the most suited contribution to our research requirements was then selected as the project’s Real-world Lab. This procedure guaranteed the participation of the municipalities, a high identification with the project, and a direct involvement of the municipalities in the transdisciplinary planning and design of the prototypes.