Vigo developed as a fishing port in the twelfth century, its narrow streets climbing steep hills above the Ría de Vigo. By the seventeenth century, the city had become a departure point for Spanish treasure fleets, and British naval raids in 1702 sank galleons loaded with silver near the Cíes Islands. The old quarter, Casco Vello, preserves granite houses and maritime trade architecture that survived those conflicts. Today, Vigo remains the largest fishing port in Europe by tonnage, and its historic center reflects centuries of Galician maritime culture. A Vigo free walking tour typically begins at Praza da Constitución, where the neoclassical city hall faces eighteenth-century merchants' houses. Guides lead visitors through Rúa Real, the medieval commercial spine, past the Collegiate Church of Santa María with its Romanesque origins and baroque additions. The route climbs to the Castelo de San Sebastián, a nineteenth-century fortress offering views across the estuary to the Atlantic. Along the way, participants learn about the city's role in the canning industry, which transformed Vigo into an industrial center by 1900. The tip-based model allows travelers to pay according to their experience, a practice common across European cities. Guides often highlight lesser-known sites: the Mercado da Pedra, a granite market hall where fishmongers sell catches from dawn, and the Porta do Sol, a modernist plaza rebuilt in the 1970s that serves as the city's social hub. Vigo's architecture reflects waves of reconstruction after fires in the eighteenth and nineteenth centuries, leaving few medieval structures intact but creating a layered urban fabric. The city's connection to the sea remains visible in its street names, murals depicting fishing fleets, and the constant presence of gulls overhead. Walking tours in Vigo offer context that independent exploration cannot. Local historians explain how the city's Jewish quarter disappeared during the Inquisition, how emigration to Latin America shaped twentieth-century demographics, and why Vigo never developed a tourist-centered old town like Santiago de Compostela. The tours conclude near the marina, where participants can see working trawlers alongside modern yachts. This juxtaposition defines Vigo: a port city that prioritizes industry over heritage branding, yet preserves authentic maritime character in its granite-paved streets and hillside neighborhoods.