Fossil and Mineral Prospecting (Nova Scotia): On the Bay of Fundy, Parrsboro is a fossil- and mineral-collector's mecca. You needn't be an expert -- a fine, accessible museum and helpful local guides will get you started. The terrain and scenery are the real draw; any finds are icing on the cake.
Upper Clements Park (Nova Scotia): About 5 minutes south of Annapolis Royal, this wonderfully old-fashioned amusement park is full of low-key amusements and attractions that will especially delight younger kids. Highlights include a flume ride (originally built for Expo '86 in Vancouver) and a wooden roller coaster that twists and winds through trees left standing during the coaster's construction.
Waterfront Walk (Nova Scotia): Halifax's waterfront walk is filled with wonderful distractions, from the province's finest museum to ships for exploring. Look also for buskers, delightful junk food, and sweeping views of the bustling harbor. If you're here in early August for the Busker Festival, it's all your kids will talk about for years.
Kings Landing (New Brunswick). History comes alive at this living history museum, where young kids are fascinated by life in early Canada between 1790 and 1910. Ask about the weeklong sessions designed to immerse kids in the past.
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 three splashing around these tepid waters while admiring pastoral island landscapes.
Terra Nova National Park (Newfoundland): This is the less noted of Newfoundland's two national parks, but the staff has gone the extra mile to make it kid friendly. There's a marine interpretive center with activities for kids, boat tours, hikes just the right length for shorter legs, and campground activities at night.