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. 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. Due to the COVID-19 pandemic in Toronto, the 2020 and 2021 editions of the event were cancelled. Highlighted buildings Most buildings are open from 10 a.m. to 5 p.m. on both Saturday and Sunday; however some only open for limited hours. The public is advised to check the "buildings to visit" section of the official website. The list of buildings is made public on May 1 of the calendar year. Some Doors Open Toronto highlighted buildings include: R.C. Harris Water Treatment Plant, Mackenzie House, and TTC carhouses. Sponsors Doors Open Toronto relies heavily on the support of sponsors. The Toronto Star releases the official Doors Open Toronto program guide in May of each year and has been a vital supporter of the program. In 2012, City TV and Omni Television also came on board as Doors Open Toronto media sponsors. Volunteers Doors Open Toronto is managed by the Cultural Services and Special Events Departments at the City of Toronto. Doors Open Toronto relies on the support, as well as enthusiasm of hundreds of volunteers. Applications are available each fall and can be found on the Doors Open Toronto website. Awards 2009 Canadian Urban Institute at the Urban Leadership awards - City Soul Award 2010 City Manager's Award for Toronto Public Service Excellence 2010 The Canadian Museums Association Awards of Outstanding Achievement Dates and themes The first Doors Open Toronto was held in May 2000. Since then, Doors Open Toronto has been held on the fourth weekend of May. In recent years, each festival has been curated around a theme. 2000: May 27, 28 2001: May 26, 27 2002: May 25, 26 2003: May 24, 25 2004: May 29, 30 2005: May 28,