The New Dutch Waterline is an ancient, unique line of defense. A defense work worth seeing: it is not only the largest national monument in the Netherlands, but since 2021 also Unesco World Heritage Site. The Nieuwe Hollandse Waterlinie consists of 45 forts, 6 fortresses, 2 castles, 85 machine gun casemates, more than 700 shelters and over 100 military locks. They are all connected by water.
The Waterlinie stretches more than 85 kilometers from north to south, from the island of Pampus near Amsterdam to the Biesbosch. The southernmost tip of the line can be found here, in the Biesbosch Line.