The CASTAL project has launched a Call for Secondary Studies on Local Sustainability Transition (LST). The aim was to promote and test the use of the CASTAL Atlas, which brings together and systematises European case studies on LST, and to support innovative, data-driven analyses of sustainability transitions across Europe. The call invited young researchers to develop (between February and June 2026) short, focused secondary studies based on the case studies and structured metadata collected within the CASTAL Atlas. 10 young researchers in the field of Social Sciences and Humanities (PhD students and Early to Mid-Career Researchers working within EU or Horizon-Associated countries) were selected. Each was given a contribution of 1,000 euros.