Do visit Gatineau Park
If you enjoy the outdoors, especially if you are a cyclist, you should definitely visit Gatineau Park just across the river from Ottawa. Bicycles can be rented during the summer months at the northeast corner of the Chateau Laurier. Ottawa and the surrounding area boasts over 170km of public paved trails on which you can run, bike, walk or rollerblade. These trails extend throughout Ottawa, to the Quebec side of the Ottawa River and lead all the way to Gatineau Park and beyond. In addition, many of these trails pass by some of Canada's most famous political and civic landmarks, making running or biking an excellent way to see the city.
Do go skating!
In winter, go skating on the longest outdoor skating rink in the world, the Rideau Canal. Skates can be rented, and refreshments purchased, from vendors right on the ice. This is also a great place to enjoy a "beaver tail" which is a local specialty - a bit like funnel cake, often enjoyed with lemon and sugar.