New Dutch Waterline
The New Dutch Waterline is a defence line that spans 85 kilometres. The line starts at Muiden and ends at the Biesbosch and is 3 to 5 kilometres wide. It consists of 45 forts, 6 fortified towns, 2 castles, 85 machine gun casemates, over 700 concrete troop shelters and casemates as well as more than 100 military sluices and water engineering works. The New Dutch Waterline is the largest National Monument in the Netherlands.