The administration building, Observatory Dome, Pre-Confederation Homestead, and other buildings are set on a 189 acre farm property in Richmond Hill. This site has a rich history in aboriginal, early Upper Canada pioneer, and later in 1933 the establishment of the University of Toronto's Astronomical Campus.

The administration building designed in 1933 by the Toronto architectural firm, Mathers and Haldenby, and the Observatory Dome by Grubb and Parson were built to the specifications of Dr. Clarence A. Chant (Father of Canadian Astronomy) and Jessie Donalda Dunlap as a memorial to her late husband David Alexander Dunlap (founder of Hollinger Consolidated Gold Mines).

The surrounding community is supporting complete designation and re-use of this site as a working musuem allowing public outreach, astronomy research and education. From 1995 with Canada's first light abatement bylaw (light pollution is not an issue) and a new heritage designation bylaw that needs to be strengthen, this Provincial and Nationally significant site can be protected. The Richmond Hill Naturalists, Observatory Hill Ratepayers, the Town of Richmond Hill and Corsica Development will be before the CRB for adjudication. Designation concerns related to this property, are the movable artefacts which are central to the heritage value of this site.