Engaging excursion along Kristervall half-bastion, discussing early modern fortifications' unique architecture, rare in Europe. Restored casemates with 17th-century cannon replicas, tools, and 16th-century weapon copies in a 'secret passage'. Explore three bastions: Kristervall, Fortuna, Spes, tracing fortification evolution. In Estonian. Duration: 45 minutes. Starts at Narva Castle cash desk.