sentences:  The observatory was built in 1963 by "Tähtitieteellis-optillinen seura" (Astronomy-Optical Society) on a small hill on lands of the home farm of Hilkka Rantaseppä-Helenius.She worked at the time as an observer at Tuorla Observatory of University of Turku.The association was founded by Yrjö Väisälä, Liisi Oterma, Hilkka Rantaseppä-Helenius, and other astronomers working at University of Turku.