There’s so much to discover in Helsinki, the “daughter of the Baltic” — and the best way to do it is from the water on a Northern Europe cruise with Holland America Line. Finland’s capital is guarded by Suomenlinna, a UNESCO-designated fortress that straddles a series of bridge-linked islets. You can pedal along the waterfront to Sibelius Park, visit the unique Temppeliaukio Rock Church, taste reindeer sausage in the restored market hall, or head out to the quaint wooden town of Porvoo.