A fractal sand castle seems like just the right sort of thing to make while hanging out on a fractal coastline. This one appears to be a Sierpinski triangle.
are so much fun to make that they have shown up in this blog before! Here are a couple fun ones that I have made recently. The first one gives you a sense of just how many strawberries I ate on my last strawberry picking trip. The second one was made with thread crochet.