They call it 'The Garden of Europe', and it's open for only 8 short weeks every spring. The spectacular Keukenhof garden in the Netherlands is said to be the largest spring flower garden in the world – and it's the highlight of our Avalon Tulip Time river cruise. BestTrip.TV filmed this once-a-year explosion of color of blooming tulips, surrounded by some of the famous Dutch tulip fields.  We were there and even we thought it was too incredible to be...