Frederikshavn is a port city in northern Jutland, the main ferry hub for crossings to Norway (Larvik, Oslo) and Sweden (Gothenburg). It's a working harbour town rather than a tourist destination, but the Skagen peninsula begins just north, making it a useful base or transit point for visiting one of Denmark's most appealing landscapes.
The town's maritime history is visible in the Krudttårnet (Powder Tower), a fortification from 1686 associated with the naval hero Tordenskiold; the Fiskerklyngen, a cluster of old fishermen's cottages; and the Bangsbo Museum, which includes a German WWII bunker that remains intact. The coastline has numerous beaches; Palm Beach is the most popular. The town is small and walkable, and free bicycles can be borrowed from the tourist office.