According to Wikipedia (https://en.wikipedia.org/wiki/Doors_Open_Toronto),
Doors Open Toronto is an annual event when approximately 150 buildings of architectural, historic, cultural, and social significance to the city of Toronto open their doors to the public for this free citywide event.
Doors Open Toronto was developed as a millennium project in 2000, by the City of Toronto (developed from a European model) and has since attracted over 1.7 million residents and tourists. Doors Open Toronto gives people of all ages and backgrounds the opportunity to learn about Toronto's history, get involved and celebrate Toronto's built heritage.
Doors Open Toronto was the first city in North America to launch this type of program. Many participating buildings organize guided tours, exhibits, displays, and activities to enrich the visitor experience.
I’ve participated off on and for about the past 10 years. This year, I focused on a small geographic area, mostly in the northeast corner of the U of T campus. I visited Koerner Hall and the Royal Conservatory of Music, the Edward Johnson Building and Walter Hall, the Faculty of Law, and then on to the Arts and Letter Club, finally finishing at the Ryerson University Ryerson Image Centre. As usual, I was accompanied by my steadfast photo buddy, Roman, and we had another fun and interesting year of Doors Open.