To protect their cities from the sea and their building sites from flooding by rivers, the Netherlands developed dike cities, dam cities, and canal cities. These three types marked three stages in the development of the Netherlands’ most successful cities.
For Amsterdam, the land was secured against flooding, by means of dikes just before the Amstel flows into the Ij (an inlet of the Ijselmeer). As early as 1200, the first groups of houses were erected on top of these dikes. In a second stage of development, the Amstel was contained by a dam (attested to in 1275) in the middle of the settlement, and here the town hall and the Nieuwe Kerk were built. The dam divided the river’s course into a lower, open, harbor and an upper, closed one. Ship traffic and all the flowing water were diverted by two new canals on the left and right of the Amstel. Later, two more moats were dug for defensive purposes and fed by water from the Amstel. Representations of the city reveal that the
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