Visiting the Netherlands

I would say you need to go one a minimum of one each of: 

• art museum (preferably old art/bigger museum but the Escher museum is pretty cool too) 
• WWII thing (Anne Frank or Corrie ten Boom are great)
• old church (it's some solid local history and architecture even if you don't care about the religious bit)
• castle (depending where you end up that might be a bit harder)

And try consuming:

• fries with satay peanut sauce and mayo, called "patat orloog" which means "French fryfry war"
• frikandel speciaal (hot dog-esque sausage with a Dutch dipping sauce and chopped onion)
• haring (herring)