Built around 1250 by local communities, the Westfriese Omringdijk is one of the oldest surviving ring dikes in the Netherlands, maintained for centuries by the inhabitants themselves through an early form of water board. To this day, every Dutch citizen still elects the guardians of the dikes, continuing a unique democratic tradition of living with and protecting against water.
https://www.youtube.com/watch?v=Lo8GbMlRJ5Y