David Dunlap Observatory

The David Dunlap Observatory is home to the largest optical telescope on Canadian soil with a primary mirror measuring more than 1.88 metres (74 inches) in diameter. Constructed in the 1930s, the Observatory is located in the heart of Richmond Hill, Ontario. The building is 18.6 metres (61 feet) in diameter and the rotating dome weighs 73 metric tons. The telescope itself weighs 21 metric tons (without its primary mirror).


For any additional information about programs, tours, schedules and more, please visit the DDO’s website.