Iglesia de San Nicolás is a Baroque church near Bilbao's old town, dedicated to the patron saint of sailors. Its location by the Casco Viejo makes it an easy architectural stop while walking between the riverfront, the market, and the old streets.
The church is not as imposing as Bilbao's cathedral or the Basílica de Begoña, but it adds a worthwhile religious and maritime note to an old-town walk.