UNaLab is a project funded by the European Union under the Horizon 2020 research and innovation programme. The UNaLab consortium is comprised of 28 partners from 10 cities across Europe and beyond, including municipalities, research, business and industry. The UNaLab partner cities commit to addressing the challenges that cities around the world are facing today, by focusing on climate and water related issues, within an innovative and citizen-driven paradigm. With three demonstration cities, seven replication cities and several observers, the UNaLab project aims to develop smarter, more inclusive, more resilient and increasingly sustainable societies through innovative nature-based solutions (NBS).