The dikes along the North Sea are so amazing.  This particular spot is very illustrative of how the Dutch have claimed land from the sea to grow crops on, pasture their animals on and live on.  These five pictures will hopefully give you a clear idea of the immense scope of these dikes.  The first picture shows fertile farmland inside the dike:

Standing in the same spot, I took this picture of the sea on the other side of the dike:

Then, I turned around and because of the curve of the shoreline, I was able to get both sea and dry land on one shot, with the dike in the middle:

Sea ...............

And dry land .............