Observatory at the Canada Science and Technology Museum where it remained until 2016. As of 2008, the building is the home to the Office of Energy Efficiency, a part of the Energy Branch, Natural Resources Canada. See also List of largest optical refracting telescopes Dominion Astrophysical Observatory (Home to 2nd largest telescope in the world in the 1910s on debut) David Dunlap Observatory (Home to 2nd largest telescope in the world in 1930s on debut) References External links https://web.archive.org/web/20070701185832/http://www.sciencetech.technomuses.ca/english/collection/dominion_observatory.cfm The Dominion Observatory – 100th Anniversary Astronomical observatories in Canada Federal government buildings in Ottawa Buildings and structures completed in 1905 Romanesque Revival architecture in Canada Geological Survey of Canada 1905 establishments in Ontario