These largely restored old walls are protected as both a Canadian National Historic site and a Unesco World Heritage site. Walking the complete 4.6km circuit around the walls outside on your own is free of charge, and you'll enjoy fine vantage points on the city’s historical buildings as you trace the perimeter of the old town. There are two other entrances: at Porte St-Louis and the Frontenac Kiosk on the Terrasse Dufferin.
In summer 90-minute guided walks (adult/youth $15/10) are also available, beginning at the Frontenac Kiosk and ending at Artillery Park. Walks depart at 10:30am, 1:30pm and 3:30pm.