Art deco walls, a 'temple of books' and other gems you won't want to miss at Doors Open Toronto

If you've ever wanted to see inside the art deco walls of the R.C. Harris Water Treatment Plant, head to the top of the mid-century Toronto-Dominion Centre or gaze up the shelves at the Thomas Fisher Rare Book Library, this weekend is your chance.

On May 27 and 28, the city is hosting Doors Open Toronto, an annual, city-wide open house of Toronto's most culturally and architecturally significant buildings and sites. 

Kristine Williamson, programming lead for the event, says this year's event will be the largest since 2019, with 150 sites taking part. 

"These buildings belong to us, right? They're part of our built heritage. They make up what we know as the city," Williamson said. "It's important that Torontonians get a chance to peek inside some of these special places."

The theme of this year's event is "city of sound." Musical performances will be hosted at places like the water treatment plant and the Fort York National Historic Site while the National Film Board will be screening documentaries, animated films and fictional shorts inside the Toronto City Council Chamber.

Most buildings will be open from 10:00 a.m. until 5:00 p.m., Williamson said, with some variation. 

Williamson recommends getting to the more popular spots early in the day, like the water treatment plant, the Legislative Assembly of Ontario and the TD Centre. 

Chris Bateman, manager of the plaques program at Heritage Toronto, will be providing tours of the TD Centre. 

"TD Centre has kind of been lost among the crowd of downtown skyscrapers now, but it's really a key building in Toronto's architectural history," he said. 

Bateman says the mid-century building was the final major work of celebrated American-German architect Ludwig Mies van der Rohe, whose work also stands in New York City and Chicago. 

"Lots of people kind of see it as this sort of final realization of his life work," Bateman says. 

Tours of the centre's 54th floor will be running from 9:30 a.m. to 3:30 p.m. on Saturday and Sunday. The floor, which is the executive level, has a "wonderfully preserved" mid-century interior, according to Bateman. 

Aside from popular spots, Williamson said some hidden gems include Coach House books, a living museum of printing history and the University of Toronto Department of Physics. 

Another one of the university's spots people should check out is the Thomas Fisher Rare Books Library, according to Petros Babasikas, director of the honours bachelor of arts program at the University of Toronto's John H. Daniels Faculty of Architecture, Landscape and Design.