I have a soft spot for this Canadian World Heritage Site as I lived in Kingston - the end (or start) of the Rideau Canal - for four years during my university days. 

Kingston is an attractive city, in my opinion, with a good collection of 19th century limestone buildings.  A particularly interesting building is the Neoclassical Kingston Penitentiary, which housed some of the most infamous criminals from 1835 to 2013. The “Kingston Pen” is now a museum with guided tours.  

Queen's University campus, a short walk from the historic downtown, also has its share of handsome limestone buildings and pleasant green spaces.

The UNESCO recognized Martello towers, i.e., Murney Tower, Cathcart Tower, Shoal Tower, were uniquely ubiquitous to the Kingston harbour, in that I had never seen them anywhere other than Kingston, but no Kingstonian appeared to take any notice of them. 

Fort Henry - also part of the UNESCO World Heritage Site - appeared just a tad out of the way for university students such as myself without a car, but we certainly were aware of its presence across the Great Cataraqui River, looming above the Royal Military College.  The first time I visited Fort Henry was through a spooky "Ghosts of Fort Henry" tour, which still runs today.  Fort Frederick is located on the grounds of the Royal Military College, but the locals are only vaguely aware of its existence.

These Kingston fortifications were built due to the fear of American invasion, and it is fair to say that the apprehensiveness to the United States of America has shaped - and continues to shape - Canadian psyche.  Canadians often self-deprecatingly or self-derisively describe Canadianness or Canadian culture as "not being American".  In all fairness to Canada, it is certainly challenging not to define yourself in relation to the neighbouring USA when it is such a great hegemonic power.  Canadianness, however, is more than in relation to USA.  Yes, it may be easy to accuse Canadians of merely listing how they are not Americans when they speak of, for example, how they are less fanatical of guns, support universal health care, are more reserved, or are less of a "melting pot" and more of a "mosaic" when it comes to immigrants.  But the fact that Canada actually managed to become "not American", despite living next to an overwhelming cultural and economic behemoth, suggests that there is indeed a distinct Canadian character, even if subtle, that allows it to write its own history.  

Canada certainly has at times made deliberate decisions to resist the American influence.  Ottawa - the start (or end) of the Rideau Canal - became Canada's capital in part due to the fact that it was on the border of French-speaking Quebec and English-speaking Ontario, but also in part because it was more defensible in the event of an American attack.  These days, Canadians worry less about an American military attack and more about an economic attack.

In terms of visiting Ottawa's portion of the Rideau Canal, I would suggest visiting it in the height of the winter when the Canal freezes and you can skate 7.8 kms of it.  To warm up after the skate, you can then visit the Canadian national historic site of Chateau Laurier hotel (photo - with Rideau Canal in the foreground) and look for renowned Canadian photographer Youssef Karsh's original signed print of "The Roaring Lion", a portrait of Winston Churchill that Karsh took during the Second World War when Churchill visited Ottawa.  As you admire the portrait, you can appreciate how fitting it is that self-deprecating Canada celebrates the person behind the camera, rather than the larger-than-life subject of the photo.