The Don Jail 1859-1864
The Don Jail is one of Toronto's most important mid-nineteenth-century public buildings. Located on a hill then outside City boundaries, it was constructed with exacting craftsmanship according to plans of William Thomas, Toronto architect and designer of other landmarks such as St. Lawrence Hall and St. Michael's Cathedral. Even though some cells measured only 1 by 3 metres, the Don Jail embodied progressive ideas of penal reform. It was once the largest prison of its kind in North America, and included a farm (now largely Riverdale Park) worked by prisoners. The building's Renaissance Revival style made jail appear suitably intimidating. Seventy executions took place on its gallows, including the last in Canada on December 11, 1962. After 113 years, the old Don Jail building was closed as a prison in 1977 - the east wing, completed in 1958, continued to serve as the Toronto Jail.
Plaque via Alan L. Brown's site Toronto Plaques. Full page here.