Best Attractions & Activities, Historic Sites: In the early days, Québec had earthen walls. But in 1832, the British erected solid stone ones as a defense against American attack. Today, it's the only walled city in North America, which earned it a UNESCO World Heritage Site designation in 1985. The interpretation centre has in-depth historical exhibits and a path, complete with interpretive signs, follows the walls making a self-guided tour easy and informative. Alternatively, there are two different 90-minute guided tours, which start at the Kiosk Frontenac on Dufferin Terrace and at the Interpretation Centre at 100 St-Louis Street. Call ahead for the schedule.