Holland's Canals, Dams, and Dikes: Holding the Waters at Bay

There's a good reason the Dutch countryside looks as it does, crisscrossed by canals and dikes, and dotted with more than 1,000 windmills. Those picturesque mills used to serve a vital role in keeping everybody's feet dry. About a quarter of the land, including most of the Randstad, lies below sea level, and without major human intervention, large swathes of the Netherlands would either be under water or uninhabitable swamps. Just imagine, when you land at Schiphol—the name, "ship's hole," is a clue—you should be about 20 feet below the surf.

The west coast has always been protected by high dunes, but the rest of the land had to take its chances for centuries. The first to begin the fight against the sea were early settlers who built mounds in the north of the country around 500 BC, and the battle has continued ever since. Real progress was made around AD 1200 when dikes began appearing. In the 14th century, canals were dug, and the first windmills were built to pump the water off the land (a job now done by electric pumps). This transformed the fertile alluvial landscape, turning it into a farmer's paradise.

War on nature has waged ever since, as Holland gradually clawed back territory by closing off the Zuiderzee inland sea in 1932 to form the IJsselmeer (IJssel Lake), and by a century-long land reclamation program of polder building. The sea bit back with a vengeance one wintry night in 1953. On January 31 that year, a combination of exceptionally high tides and strong winds sent a storm surge pouring up the Rhine delta, killing around 2,000 and inundating 1,000 square miles of land.

Dutch engineers vowed this disaster would never be repeated. They responded by building the Delta Works, one of the great engineering feats of the 20th century.