Non existing. Basically every building in Holland is build on 'stilts'. 40-100 feet long beams of wood or concrete that reach through the 'bog' surface until it

Non existing. Basically every building in Holland is build on 'stilts'. 40-100 feet long beams of wood or concrete that reach through the 'bog' surface until it reaches a stable layer of sand. See https://youtu.be/5GEGWP95HFw?t=2m0s https://youtu.be/5GEGWP95HFw?t=2m0s for an example of how those stilts are placed. Note that until 2:30 it's basically just using a big weight. From about 2:40 the machine starts to get serious. Beyond dikes we've had mills keeping ground water levels steady since at least the 10th century.