Different audiences visit science centres and science festivals, but prisoners are a category of people who have difficulties to approach science, because of the impossibility to visit museums and exhibitions. A lot has been said about the possibility that prisoners might be able to break the cycle of crime if they could receive quality education while they are still behind bars, but this education has virtually no science content and is almost never really interactive. Here we will report three cases of interactive science activities run in Italy, Greece and Austria .