It was a 7-day river cruise aboard the Amadeus Princess.  Stops included Amsterdam, Volendam, Edam, Arnhem, Middelburg, Ghent, Bruges, Antwerop, Kinderdijk and the Keukenhof Gardens with over 4 million tulips and 3 million other spring plants.  Kinderdijk is a UNESCO World Heritage site with 19 working windmills.