Tuorla Observatory is the Department of Astronomy at the University of Turku, southwest Finland. It is the largest astronomical research institute in Finland. Together with the Space Research Laboratory at the Physics Department of the University of Turku, it forms Väisälä Institute of Space Physics and Astronomy (VISPA).HistoryTuorla Observatory was established in 1952 by professor Yrjö Väisälä. A new observatory was needed because the old Iso-Heikkilä Observatory close to the centre of Turku started suffering heavy light pollution from nearby city and especially industrial areas to the south of the observatory. A new place was found in Tuorla, which is one of the small villages in (former) Piikkiö municipality. It is located about 12 kilometres from Turku in the direction of Helsinki.The first part of the observatory contained a main building and 51 meter long tunnel for optical research. Due to the growing size of the department, new parts to it have been built in 1989 and 2002. Starting in 1974, the observatory was part of the Physics Department until 1991 when it became again an independent research institute of the university. In 2009 observatory reunited with physics department and is one of the seven laboratories of Department of Physics and Astronomy at University of Turku.The observatory has several telescopes located around the main buildings and also international telescopes like the Nordic Optical Telescope are in use. The one meter Dall-Kirkham reflector () is the largest optical telescope in Finland.