heureka’s outdoor exhibition area, science park galilei, opened in 2002. this area of the centre can be visited annually during the summer season. galilei is a sort of “scientific playground”. the 7,500 m2 area holds dozens of exhibits, many of which feature water as the primary element. the exhibits are based on mathematical, physical and musical phenomena. the outdoor park also contains moving works of art, such as the sand plotter created by well-known finnish artist osmo valtonen. galilei also features an arboretum with species of conifers from the northern hemisphere.