David Dunlap Observatory (David Dunlap Obs.Univ.of Toronto), located at the University of Toronto, Mount Richmond, Canada, at an altitude of 244 meters, with geographical coordinates of 5 17.7 west longitude and 43 51.8 north latitude.[1] David Dunlap Observatory has a caliber of 188cm, caliber ratio of N5, and the telescope of Cs18, which was completed in 1935.