A friend had the brilliant idea to take a sailing trip on the wadden sea under the Frisian islands. It’s a protected piece of nature because of the varied wildlife and general uniqueness. The boat we went on was a 19th century freight carrier with a flat hull and sails. http://www.willemjacob.nl
On board were a man from a local planetarium and a woman from the society for protection of the area. Once we’d sailed out on to the sea and the anker was lowered they had fascinating stories to tell about the effects of the solstice on the flora and fauna in the sea.
We learned about the trajectory of the moon and other planets. How the moon and the earth pull toward each other causing the tides. How sand gets carried along by the current and deposits itself to create land along the islands. How mussels and other shells dip under the sand to protect themselves from birds trying to suck them out.
It was a fun experience well worth a repeat. Learning about that area is very interesting.