Nauru string figures
The string figures of Nauru are among the most complex patterns produced on string in the world. The island nation of Nauru is the home of an anthropologically fascinating ethnic group whose customs are very similar to those on Polynesian islands.
Some of those Nauru string figures are really beautiful! I have a book that shows how to make them, but they're so tricky, I think I'll have to learn from a a pro like ISFA's Joe D'Antoni!