Forte de Santiago da Barra in Viana do Castelo

In Viana do Castelo’s commercial docks is a 16th-century fortress, guarding the anchorage in the Limia Estuary and what used to be one of Portugal’s major seaports. This building replaced an earlier fort, and in the last decades of the 1500s was equipped with all of the elements developed to counter artillery. The walls have a trapezoidal outline on a pentagonal plan, with bartizans at the angle of the bastions. The fort isn’t bursting with interest, but it’s a sight to keep in mind: To enter you have to cross the dry moat and pass through a vaulted tunnel, and from the walls you can contemplate the Limia Estuary or the Hill of Santa Luzia.