The south wing addition to the Art Gallery of Ontario (AGO) was a major part of the 2008 Frank Gehry redesign of the historic Toronto landmark. Dubbed the “barnacle” by the architect, a signature element of the design is the spiral staircase that projects from the otherwise flat, glass and metallic blue façade. Photographer Brian Carson captures this unique architectural piece in this beautiful black and white image submitted in the UrbanToronto Flickr pool.

The Art Gallery of Ontario's South Wing Spiral Staircase, image by Brian Carson