It’s worth exploring the Bangsbo area, 3km south of the town centre. The main drawcard is Bangsbo Museum, an old country estate with an interesting mix of exhibits. The manor house displays antique furnishings and collectables, while the old farm buildings house ship figureheads, military paraphernalia and exhibits on the Danish Resistance during WWII.
The most intriguing exhibit is the Ellingå ship, the reconstructed remains of a 12th-century Viking-style merchant ship that was dug up from a nearby streambed.
Bus 3 from central Frederikshavn stops near the entrance to the estate, from where it’s an enjoyable 500m walk through the woods to the museum. There's an adjoining Bangsbo Botaniske Have (botanic gardens) and a Dyrehave (deer park); both are good for picturesque strolling or picnicking.
Bangsbo Fort, about 800m over the wooded ridge from the gardens, is an atmospheric WWII bunker complex housing some big guns and commanding views across to Frederikshavn and out to sea.
The admission ticket is valid for a week and covers entry to a few other museums in northern Jutland.