Final answer:
The second largest city in Portugal on the northern coast is Porto, a key cultural and commercial hub with historical significance and modern architecture.
Step-by-step explanation:
The second largest city in Portugal, located on the northern coast, is Porto. Known for its significant historical and commercial importance, Porto has been a hub for trade and logistics since medieval times. The city's architectures, like the Estadio Municipal de Braga designed by Eduardo Souto de Moura, reflect the cultural richness and contemporary design that defines Portugal's urban landscape. While Lisbon serves as the country's most populated metropolis, Porto stands out as a crucial center for commerce, tourism, and culture in Portugal.