Toronto is home to several lost observation decks, mothballed one by one over the years as their importance was overshadowed by taller structures.

Many locals know of the opulent gargoyle-lined observation deck sitting abandoned atop the Commerce Court North tower, though the complex in Toronto's Financial District is also home to another lesser-known lookout that has been off-limits to the public for almost a half-century.

Commerce Court West opened in 1972, a shimmering metallic edifice by legendary architect I.M. Pei that took the crown of Toronto's tallest building at 287 metres in height.

Commerce Court West once towered above the Toronto skyline - it is the city's seventh-tallest building as of 2023.

The 57-storey tower would only hold onto that title briefly, reigning as the city's tallest structure for just three years before being overshadowed by First Canadian Place in 1975 and the CN Tower a year later.

But, for a brief few years between Commerce Court West and the CN Tower's openings, tourists looking to get the best views of Toronto flocked to this office tower at King and Bay.

The building's observation deck opened in 1973, the year after the tower completed construction. A trip to the top of the building cost visitors 50 cents in the mid-70s ($2.68 adjusted for inflation in 2023), and the space was available to enjoy until as late as 10 p.m.

Photographer John Briggs shared a set of almost half-century-old photos captured in the long-lost observation deck with blogTO, which he believes were shot in 1975 with his then-new Nikon camera.

Photographer John Briggs on a visit to the CIBC observation deck in 1975.

Briggs remembers the observation level for its unique quirks, like reflective glass that made for often-confusing views, and mirrored panels above windows.

He noted the observation level was known for "strange reflections in the corner windows," explaining, "I can't remember how they were so clear for the camera, but I think the windows were a high reflective surface and the room was low light."

"The mirror above the window was a unique feature at the time that showed the streets below," says Briggs. A similar feature would later be introduced at the CN Tower's main observation pod.

Mirrored panels fixed to the ceiling offered views of the streets below.

The short-lived observation floor on the 57th floor of Commerce Court West is often overshadowed by other disused observation decks in Toronto, like its neighbour at Commerce Court North, as well as shuttered lookouts at City Hall, the Canada Life Building and the TD Centre.

The view facing north over Bay Street has changed considerably since the mid-1970s.

Like its fallen brethren, the Commerce Court West observation deck's limited lifespan was the product of changes in the surrounding city. Taller towers hemmed in views, logistical challenges of tourists hampered the operations of office buildings, and perhaps most notably, the CN Tower was just…better.

Reflective windows often made for confusing views, like this one featuring the CN Tower and First Canadian Place - two structures that ended CIBC's reign as the tallest.

The lookout closed in mid-1977, just four years after opening and a little over a year after the CN Tower's observation decks began welcoming visitors.

The CN Tower's main observation deck offers views from 100 metres higher up, and its SkyPod even further from the ground, giving Commerce Court little hope of survival.

Following the observation deck's closure, the space was later used as an executive space for CIBC, though the banking giant has since relocated its headquarters to the new CIBC Square complex a short distance to the south at Bay and Lake Shore.

The Commerce Court complex is now home to two disused observation decks, though a third is on the way. A third tower is planned for the complex, set to include a new outdoor observation platform that would once again see tourists flock to the Financial District for panoramic city views.