1789 AX Huisduinen
Napoleon himself ordered the construction of Fort Kijkduin in what he called "the Gibraltar of the North". This will get you through the afternoon, because in addition to the history of the fort and its occupants you can find a sea aquarium with a glass tunnel and fish you are allowed to touch!
Not only the North Sea is dealt with here in the sea aquarium, but also fish migration to the Waddenzee. Fort Kijkduin after all is situated at a location where the North Sea and Waddenzee merge. The fish kept in the aquarium naturally appears in both areas.