REINFORCE (Research Infrastructures FOR citizens in Europe) is a Research & Innovation Project, supported by the European Union’s Horizon 2020 SWAFS “Science with and for Society” work programme. The project will create a series of cutting-edge citizen science projects on frontier Physics research, with citizen scientists making a genuine and valued contribution to managing the data avalanche. More than 100,000 citizens will be engaged in the research done in Large Research Infrastructures through a participatory design methodology that will take into account the special characteristics of different target groups, their barriers and constraints, their perceptions and biases and their attitudes and knowledge regarding science. They will use real and simulated data for analysis, simple affordable detectors and instrumentation to measure properties of objects such as cosmic rays, providing among others their contributions in large infrastructure site specific parameters such as environmental impacts and noise. Furthermore, through the use of open data as with dedicated training activities on their use and analysis, citizens will be able to perform their own inquiries, guided and supported by the REINFORCE experts.