collaboration with the Mint of Finland to mark the company's 150th anniversary. The exhibition Intelligent City is about utilising information technology in improving the functionality, safety, energy effectiveness and environmental friendliness of a city. As an extension of the main exhibition, the Heureka Classics exhibition was opened in 2009 in honour of Heureka's 20th anniversary, and hosts a collection of favourites both from Heureka and from other science centres. The exhibition shows various prominent physical phenomena, which can be experienced by the entire body. Illusion exhibits show how the cooperation between the brain and the senses create amazing phenomena inside our heads. From the beginning of August 2009, Heureka has also had the Science on a Sphere exhibit on display. This exhibit is a large sphere created by the American National Oceanic and Atmospheric Administration (NOAA), with various demonstrations of the climate, the oceans, the landmasses and astronomical objects projected on its surface. In addition to the main exhibition, Heureka generally also houses two temporary exhibitions. The topics of past temporary exhibitions have included, for example, dinosaurs, humans, sports, forests, the art of film, flying and ancient cultures. Since Heureka's opening, the most successful exhibitions have been the dinosaur exhibitions. The 2001 exhibition about the family life of dinosaurs, for example, attracted 406,000 visitors. Many of the exhibitions independently produced by Heureka have made guest appearances in numerous science centres all over the world. Heureka also features exhibitions imported from abroad. Outdoor areas 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. The area in front of Heureka features a permanent bedrock exhibition, which contains both common and rare types of rocks found in Finland's bedrock. The rocks are situated to reflect their distribution throughout different geographical provinces of Finland. The purpose of the bedrock exhibition is to show visitors of the science centre that the message of the science centre is not limited to technical achievements, but