Viking cruise ships enter the Netherlands from Germany, the first stop is Rotterdam's children's dike. Speaking of the Netherlands, tulips, wooden tracks and windmills blurted out, while the children's dike is the most reserved place for large windmills in the Netherlands. The Netherlands is the lowest landed country in the world. In ancient times, it used to build dams and drain out of windmills, and the windmills also did some grinding work. Now of course, it will not use windmills to drain, but as the "national essence" of the Netherlands, and open sightseeing as a scenic spot.