The polders are characteristic for the landscape of North Holland. A polder is a low-lying tract of land enclosed by dikes that forms an artificial hydrological entity, meaning it has no connection with outside water other than through manually operated devices. The first polders were constructed in the 11th century.
The last flooding disaster was in 1953. After the disaster, the Dutch government improved the dikes and flood defences. Polders are at risk from flooding at all times, and care must be taken to protect the surrounding dikes.
