The activity demonstrates the generation of entangled photon pairs through the Spontaneous Parametric Conversion (SPDC) process in nonlinear BBO (Beta-Barium Borate) crystals. Participants will perform a simplified Bell test and will have to adjust polarizers and record measurements, directly observing the violation of the CHSH inequality: an experimental test of quantum entanglement. Each session includes a brief introduction, the performance of the experiment and a final discussion of the results. The set-up requires a dark room, standard electrical connections and the support of staff to guide and supervise the activity. This is a unique opportunity to explore in an interactive and accessible way one of the most fundamental aspects of quantum mechanics.