Houseboat Museum (Amsterdam)

Step aboard the Henriette, a 1914 cargo barge turned houseboat museum, where the 50-square-meter interior reveals how 40% of Amsterdam's houseboats are still used as primary residences. Unlike Delft's moving tour (#6), this is a stationary experience, but it offers 30% more historical artifacts per square meter than the average houseboat. Entry costs €5, making it the cheapest attraction on this list—60% less than #7's Light Festival cruise. You'll see original wood-burning stoves and a 1920s kitchen, plus learn that 2,500 families now live on Amsterdam's canals.