As one descends through the Don Valley from the north, the first of the two viaducts spanning the impressive valleys appears as the valley makes a turn to the west. This span, the Leaside Bridge, carries Millwood Rd above the valley and was built to link the young town of Leaside to the rest of Toronto via the village of Todmorden.

Formerly known as the East York Leaside Viaduct, and officially commemorated as the Confederation Bridge, is a truss arch bridge designed by engineer Frank Barber. Standing 45.4 metres (143.8 feet), it is taller than the widely recognized Prince Edward Viaduct to the south by 5.4 metres (34 feet). The bridge was constructed in a record 10 months in 1927, with work starting in early January and the commemoration taking place October 29.

Since construction, the bridge has undergone expansion and renovation - in the late 1960's, the bridge was widened to six lanes, which required additions to the truss underneath (the diagonal beams visible from the valley below that extend out from the box truss). In 2005, the bridge was renovated, and the original decorative handrail, removed in the expansion, was added back to the structure.

Traversing the underbelly of the bridge is not for the faint of heart. A single catwalk, wide enough for only a single person, extends across the span, with low beams from the truss crossing it. These beams, as I learned the hard way, are low enough to smash ones head into. It was not a pleasant experience.

Nor was the discovery that, unlike the Hogg's Hollow Bridge, the Leaside Bridge shakes and vibrates significantly as traffic crosses overhead. It took a bit of getting used to, to be certain. Crossing over the Don Valley Parkway was also an experience... I'm convinced that motorists, if they were paying attention, could have seen me up on that catwalk as they approached.

The bridge offers some spectacular views of the valley and the Parkway, however, along with some interesting graffiti and tags. Some of the tags are located in places that made my heart skip a beat when I thought of how the graf artists had got out to leave their mark.

Would I do Leaside again? Probably not, but that's because there really isn't much to her. The first visit was fun and interesting, though, and made my afternoon.