The David Dunlap Observatory (DDO) is an astronomical observatory site just north of Toronto, in Richmond Hill, Ontario. Formerly owned and operated by the University of Toronto, from its establishment in 1935 until 2008; the observatory is now owned and operated by the City of Richmond Hill providing a combination of heritage preservation, unique recreation opportunities and a celebration of the astronomical history of the site. Its primary instrument is a 74-inch (1.88 m) reflector telescope, at one time the second-largest telescope in the world, and still the largest in Canada. Several other telescopes are also located at the site, which formerly also included a small radio telescope. The scientific legacy of the David Dunlap Observatory continues in the Dunlap Institute for Astronomy &