Science & Society Together - the founding of the Citizen Science Lab in 2018 is a classic Leiden story of academic grassroots initiative. Astronomer Frans Snik and Astronomy & Society researcher Pedro Russo together with Science Communications & Society researcher Anne Land-Zandstra saw the need and the potential based on their own experiences of Citizen Science, such as in the iSpex project, where particulate matter is measured using your smartphone. Since then, the Citizen Science Lab has been supporting colleagues across all faculties and facilitating new research collaborations with citizens and societal actors on urgent societal issues such as air pollution, biodiversity collapse, and the energy transition.