Science Recreation Workshops (SRW) are engaging activities intended to create scientific experiences for participants, who play with natural phenomena while they explore, discover, discuss, and learn about them. They take people into a first-hand scientific adventure. SRW's do not demand a lot of resources to develop, that is why SRW's groups can operate 'guerrilla-like' tactics: with fast-moving and small-scale actions to get people to enjoy and learn science in all kinds of contexts. It is possible to take SRW's to a wide variety of places: museums, parks, schools, public squares, streets, marginal neighborhoods, and small towns. It could be said that SRW's present an interesting dichotomy: their versatility allows them to go where other science communication activities cannot reach, but they hardly appear in the literature on informal science education or public communication of science and technology. SRW's have developed without barely having scholarly discussion about them, but this kind of work poses constraints for their development. Tasks such as improving their activities, training new practitioners, and impact evaluation demand for a solid bedrock. In this article, we intend to characterize SRW's -- alongside the organizations devoted to their development--, in an initial effort to spark discussion about them.