Hogs Back Falls are a series of man-made waterfalls on the Rideau River in Ottawa, located just north of the point where the Rideau Canal splits off from the river. The site makes for spectacular photography in all seasons, and I'd be hard-pressed to pinpoint my favourite time of the year to visit them. If I had my way, I'd be there every week! :-)
The dam at Hogs Back was raised as part of the Rideau Canal construction project in the 19th century, in order to divert water from the Rideau River and into an artificially-created waterway leading to the Ottawa locks. The building of the dam was one of the biggest challenges in the Canal construction project; the dam collapsed three times during construction, but was finally completed in 1821. See here for a detailed account of the construction project on the Rideau Canal web site.
From a photographer's point of view, Hogs Back provides fast water, slow water, extremely cool rock formations and a stunning setting for outdoor portraiture. Fog is frequent in the spring and fall, and the terrain offers wonderful opportunities for creative angles and dazzling perspectives. In the summer it's possible to catch a great blue heron, but you'll need a good zoom. Astoundingly enough, I've also seen kayakers jumping the falls, but that was probably a once-in-a-lifetime capture!
If you're driving, there's public parking right next to the falls off Hogs Back Drive. For transit users, the easiest way to get there is to take the No. 87 up Riverside Drive, get off at Hogs Back and walk to the falls. Another option if you're setting off from downtown is to take the No. 3 Colonnade and get off at Prince-of-Wales and Meadowlands. There are public washrooms near the snack bar, open in the daytime during the summer months. Dogs are allowed on a leash.