Take a behind-the-scenes tour of Ottawa’s oldest stone building. The Bytown Museum offers tours of the Commissariat Building throughout the day. Come check out their new temporary exhibit and award-winning gallery renewal, a showcase of their historical costume collection and their vault. Enjoy a fresh lemonade next to the Ottawa lockstation, part of the Rideau Canal UNESCO World Heritage Site.

The ByWard Market has been the focal point of Lowertown since 1848. This particular site has served as a market since 1875. The present building, designed in 1927-28, is the fifth to house Ottawa’s public market. The ByWard Market Building is home to food merchants, specialty boutiques and artisans operating in a mix of indoor and outdoor spaces.

With over 17,000 artworks by over 3,000 artists, the Canada Council Art Bank houses the largest collection of contemporary Canadian art in the world. The collection houses paintings, sculptures, drawings, photographs and prints by emerging and established artists, including a significant number of artworks by Indigenous artists. The collection is also regularly featured at the Canada Council for the Arts.

The Ottawa Hospital is a world leader in cancer research. During Doors Open, discover fascinating cancer research with a behind-the-scenes tour of a lab, and an opportunity to explore the lab’s high-tech tools. For safety reasons, visitors must be 16 years or older. Forty-minute guided tours leave every hour from the Cancer Centre lobby. Space is limited. Registration is required.

The Cumberland Heritage Village Museum provides visitors with an immersive, seasonal experience that showcases rural life in the 1920s and 1930s in Eastern Ontario. Tour an operational sawmill and blacksmith shop, a one-room schoolhouse, a 1927 Imperial Gas garage, a 1904 church and family homes. This year, they are excited to welcome Ottawa Fire Services back to the museum.

The Diefenbunker is Canada’s most significant surviving Cold War artifact. It is an impressive four-storey underground facility that operated as the country’s central communications headquarters during the Cold War, ready at any moment in case of a nuclear attack. Now a museum, the Diefenbunker offers a one-of-a-kind experiential learning environment, coupled with award-winning programs, events and exhibitions.

The Gladstone Theatre has been a theatre for over 40 years. Initially a garage, it was turned into a 230-seat theatre in 1983 by the Great Canadian Theatre Company, with further renovations in 2007. By 2016, it was regularly hosting 12 stylistically diverse theatre companies, with more than 27,000 tickets being sold per year. Come and explore this unique site!

The Herb Garden is pleased not only to celebrate 30 years as a small family-run business operating a greenhouse in rural Ottawa, but also a 200-year-old farm property and heritage barns. During Doors Open Ottawa, visitors can explore the historical barns and learn about the family business before checking out the trails, labyrinth and garden.

The Ingenium Centre houses Canada’s science and technology collection, with more than two million archival, trade literature and library materials, and more than 116,000 artifacts. The Centre provides a controlled environment to protect the artifacts for the benefit of generations to come, designed to properly house artifacts made of materials such as plastic, wood, paper, textiles and ivory.

Established in 1992, the Jami Omar Mosque was located inside a renovated bungalow. But, in 2003, construction began on a new mosque located on the same property. Over the next 15 years, the new and much larger mosque was constructed. It provides various services for the community — including marriages, family counselling and funeral services.

The Library and Archives Canada (LAC) is located in a prominent structure, comprising two symmetrical four-storey wings that wrap around a central nine-storey tower block. This year, visitors are invited to stop by the building to learn about the LAC’s extensive services for the public and to hear more about their future home at Ādisōke, scheduled to open in 2026.

Founded in 2019, the Ottawa Glassblowing Co-op is located in the heart of Ottawa near Little Italy. Their mandate is to foster a glassblowing co-operative that operates inclusively to support the artistic creativity, learning and growth of its members and to educate the public in the art of glass. Come and see glassblowing demos by local artists!

The Carleton County Jail was built in 1862 and was run as a prison for 110 years, with a capacity for approximately 150 prisoners at a time. In 1972, the jail was shut down due to inhumane living conditions. But it was repurposed and opened a year later as the Ottawa International Hostel. Pre-registration is required for this site.

The Ottawa Little Theatre, founded in 1913, is Canada’s longest continuously running community theatre. During Doors Open Ottawa, visitors will receive a guided, behind-the-scenes tour from one of the theatre’s dedicated volunteers. The tour will reflect an actor’s experience from first rehearsal to opening night and feature the talented production team who support them on that journey.

Located in the busy ByWard Market area, the Ottawa School of Art is a four-storey, three-bay stone building of solid appearance with a richly decorated principal façade. During Doors Open Ottawa, visitors are invited to join school staff and students in the lobby as they celebrate the school’s 145th anniversary. Throughout the day, art and artifacts will be on display.

Rideau Hall has been the official residence of every Governor General of Canada since 1867, and their workplace since 1940. It has nearly two centuries of history, and has become an important gathering place and site of official activities. The grounds, the building and its interiors have evolved over time to reflect/reinforce Rideau Hall’s identity as a national symbol.

Suntech is a commercial greenhouse that supplies Ottawa's grocery stores with tomatoes and cucumbers. They use hydroponics to reduce water consumption and give exact nutrients to the plants in conjunction with LED lights in certain crops. They also focus on providing the highest quality vegetables to local markets, meaning that their carbon footprint is reduced. Don’t miss the tasting tables!

A tour of this site by one of the guide-interpreters is a unique way to learn about the building, its massive scale and commanding entrance hall. Architect Ernest Cormier’s art deco design enhances the natural beauty of the exquisite woods and marble interior. For Doors Open, only the Grand Entrance Hall and the Main Courtroom will be open.

The capital region’s only therapeutic riding facility accredited by the Canadian Therapeutic Riding Association provides therapeutic riding lessons and equine-assisted programming for children and adults with physical, developmental and learning disabilities. Situated on over 8 hectares (20 acres) of pasture and trails, this fully accessible facility includes an indoor and outdoor arena, box stalls and a classroom for additional programming.

Built in 1860 along the shores of the Rideau River, Watson’s Mill remains active as a water-powered flour mill. Nearby Dickinson House, built in 1867, displays the heritage home of the past mill owners. Dickinson Square is the only industrial heritage site in Ottawa. The site comes to life through tours by costumed interpreters and milling demonstrations.