Fundy National Park and Vicinity (New Brunswick): You'll find swimming, hiking, and kayaking at this extraordinary national park. And don't overlook biking in the hills east of the park or rappelling and rock climbing at Cape Enrage.
Prince Edward Island's Beaches: The red-sand beaches will turn white swim trunks a bit pinkish, but it's hard to beat a day or two splashing around these tepid waters while admiring pastoral island landscapes.
Ottawa (Ontario): In this family-friendly city, you and your kids can watch soldiers strut their stuff and red-coated Mounties polish their equestrian and musical skills. Canoeing or skating on the canal is lots of fun, and Ottawa boasts a host of lively museums to explore -- such as the Canada Aviation Museum, the Canadian Museum of Civilization, and the Canada Science and Technology Museum.
The Muskoka Lakes (Ontario): This region is filled with resorts that welcome families. Kids can swim, canoe, bike, fish, and more. Since most resorts offer children's programs, parents can enjoy a rest as well.
Whistler/Blackcomb Ski Resorts (British Columbia): Whistler and Blackcomb's twin ski resorts offer lots of family-oriented activities. You'll find everything from downhill and cross-country skiing, snowboarding, snowshoeing, and snowmobiling lessons in winter to horseback riding, mountain biking, golfing, in-line skating, paragliding, heli-skiing, swimming, kayaking, and rafting summer trips designed for families with school-age children.