Dutch water line (Hollandse waterlinie)

   During the Dutch Revolt, the Dutch stadtholders used the flooding of land as a strategy against the enemy. In the 17th century, a defenseproject was realized with dikes, sluices, and fortifications to protect the province of Holland. Polders could be easily inundated. The first water line proved to be successful during the French attack of Louis XIVin the war of 1672. The system was modernized and shifted eastward in the province of Utrecht during the 19th century, the new Dutch water line. During World WarII, the Dutch started their defense even fur ther eastward, but they were forced to surrender before they could use the new water line.

   Another well-known defensive water line is the Stelling van Ams terdam, which was built during the period 1880–1920 (135 kilome ters/84 miles around Amsterdam). The Stelling, which includes 42 fortifications, became a United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Sitein 1996.

   See also Fortresses.