At First I Wondered What I Was Looking At,

whales, octopus and giant lobsters,

then it became clear, it was the Scheveningen Kite Festival, and for this September the SeaLife Display Renesse Kite Festival 2018, running from September 29, 2018 - September 30, 2018, a  bit late for this year but a note in the diary for next, 

it featured over 100 world wide entries, and you can even buy a kite at the festival and fly it yourself, what a great day for the family, I must remember to look for it next year.