Your signature says "even an aviation site such as POA, is seldom your best bet for good information. You will learn that on POA and other online sites that you will get widely different answers and that most will be wrong or at best incomplete.".
I probably best suggest a link like https://www.holland.com/global/tourism.htm
For what it is worth; aviation interest; the museums at Lelystad aerodrome (civil) and Soesterberg (military).
For cities I like Rotterdam and Delft. For historic smaller towns e.g. Elsburg, Zaltbommel and Naarden are worth a visit. All nature is cultivated in the Netherlands, but these are nice places (e.g. Biesbosch). The Deltaworks are interesting. Although crowded, you should not miss the Rijksmuseum in Amsterdam, and take a walk in the city center. The islands of Texel (airfield there) and Terschelling are nice for a one night visit. Belgium also has great historic towns to visit, particularly in Flanders. See https://www.visitflanders.com/en/?country=en_US
His other handle is Captain.... look it up.