[2][4] The three-story parged brick building has castle-like features and Gothic details.

[1] The courthouse features a stone foundation housing the cell blocks, squared mortar-covered brick walls to give a stone-like appearance, octagonal towers, a polygonal bay, tall lancet windows, secondary square windows and distinctive crenelations.

[3] The building was designed in the Gothic Revival style by Toronto architect John Ewart, and constructed from 1827 to 1829.

In 1955, it was designated a National Historic Site because [I]t is a very early example of the Gothic Revival style, pre-dating the earliest important Gothic Revival public building in England, the Houses of Parliament.

[1]The exterior of the building and the scenic qualities of the landscape, are protected by an Ontario Heritage Trust conservation easement.