Guided walking tours of the three-mile (5km) long city wall that surrounds the old city of Québec trace the evolution of the city's defence system across three centuries. The walls are set with interpretation panels. Quebec is the only fortified city in North America and this fact contributed to its being named a World Heritage City. Visitors can also view the Esplanade Powder Magazine.

Address: 100 Rue Saint-Louis (tours depart from the Frontenac kiosk, Dufferin Terrace)

Website: www.pc.gc.ca/fortifications

Telephone: (418) 648 7016

Opening times: Daily from 10am to 6pm (16 May to 5 September); Daily from 10am to 5pm (6 September to 10 October); Open by reservation between October 12 to May 7

Admission: C$3.90 (adults), C$1.90 (youths). Guided walk plus access to the Learning Center: C$9.80 (adults), C$4.90 (youths)