Why is the Netherlands so flat and so wet?

It is a river delta with the sea kept out by machinery. About a quarter of the country lies below sea level and something like half is under a metre above it, and much of that land was made rather than found - drained from lakes and seabed since the Middle Ages, first by windmills and now by pumps that never stop.

That produced an unusual politics. Keeping the water out cannot be done by one landowner, so medieval communities formed water boards to build and maintain dykes, with elected officials and the power to tax - institutions older than the Dutch state itself, and still running today. The consensus-seeking style Dutch politics is known for has a plausible origin in the fact that a neighbour who neglects his dyke drowns you too.

The engineering is on a scale that is hard to picture. The Delta Works, built after a 1953 flood that killed over 1,800 people, is a system of dams and storm barriers protecting the southwest, including a barrier with gates the size of the Eiffel Tower lying on their side that close only when a surge is forecast. The current approach has shifted from holding every line to giving rivers room to flood in places chosen in advance, on the reasoning that a system with no give in it fails all at once.