The David Dunlap Observatory is Canada's largest optical telescope with a primary mirror measuring more than 1.88 metres (74 inche...
The David Dunlap Observatory is Canada's largest optical telescope 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).
Summer Astronomy Programs
We offer a variety of family programs, heritage tours, and lectures where participants can visit the RHDDO in-person and explore the night sky, discover the cosmos and learn about the history of this unique National Historic Site! Pre-registration is required to participate in our programs or workshops.
Astronomy Family Night Astronomy Speakers Nights How to use your telescope Space Fun Up in the Sky Planetarium Days Sunday Sungazing
Please Note: Many of the RHDDO programs have admission requirements. Please carefully read the description of the program and custom questions throughout the registration process.