The Site

The Netherlands is famous for its age-long struggle with water. At times, however, water was an ally. In the past, land was intentionally flooded during times of war in order to obstruct the enemy. One of the most well-known water defence lines in the Netherlands is the Nieuwe Hollandse Waterlinie – the New Dutch Waterline, also referred to as “Holland’s secret weapon”. This defence line is almost 85 kilometres long and three to five kilometres wide.

Consisting of an ingenious system of sluices, dikes and canals, the New Dutch Waterline defended the western part of the Netherlands. A shallow layer of water, about 40 to 50 centimetres deep, was enough to make the land treacherous and difficult to pass for soldiers, wagons and horses. At the same time, the water was too shallow to cross with boats. Vulnerable higher-lying areas along the natural defence line were strengthened with forts, bunkers and group shelters. The line included five fortified towns.

Although the New Dutch Waterline never had a chance to prove its worth as a line of defence, it has been brought into a state of emergency three times. First in 1870, when the Franco–Prussian War threatened to turn into a European war, secondly during World War I, and finally in 1939, with the outbreak of World War II.

The New Dutch Waterline is on the Netherlands’ Tentative World Heritage List. It is a cultural heritage site listed as an extension of the Defence Line of Amsterdam, which was added to the World Heritage List in 1996.

Lessons learned during the construction of the New Dutch Waterline (1815 – 1940) were applied during the construction of the Defence Line of Amsterdam (1881 – 1940). The Defence Line of Amsterdam is the culmination of the New Dutch Waterline. Together, the two waterlines tell the story of this unique use of water and water systems for the defence of the political centre of the Netherlands.

Nowadays the forts have different purposes, such as congress centres, wine cellars, campsites, museums, restaurants or nature reserves. They give new meaning to the defensive works and generate financial benefits for its preservation and maintanance. People enjoy the many beautiful recreational routes set out in the military landscape and many forts offer guided tours. These new functions help to preserve this cultural heritage.

The forts remained closed to the public for decades after they ceased to be used for military purposes, and nature was allowed to run its course. Therefore, a lot of forts are special in ecological terms, with a very rich collection of plants and lots of rare species. Many forts with their cracked brickwork are renowned for their bat populations.


The Project

The World Heritage Volunteers project at the New Dutch Waterline aims to preserve and maintain important parts of the former defence line such as forts and bunkers. Under the supervision of experts, local volunteers and workers, the World Heritage Volunteers maintain and restore forts, bunkers and the surrounding landscape. The international volunteers help by pruning trees, cutting grass, cleaning bunkers, painting bridges and restoring paths in the grounds of the forts. To support the surrounding wildlife the volunteers make objects such as houses for insects and for owls and breeding places for grass snakes.

The volunteers help promote the cultural heritage to the local and regional public by creating recreational facilities within the area. One example of this is the construction of a pull ferry for children, as part of a ‘kids proof’ walking path next to one of the Waterlines biggest fortifications. Another example is the ‘bunker trail’, a short walking trail along several military bunkers. To make these bunkers more visible and create awareness in an unusual way, they have been marked with “haiku”, Japanese poems, by using reverse graffiti. The volunteers have made their own haiku inspired by the New Dutch Waterline, World Heritage and intercultural exchange.

The involvement of the World Heritage Volunteers is very important; without them, many projects could only be carried out much later or not at all. The fort owners are very pleased with the extra help from this project. Besides all the practical results, the awareness raised for World Heritage is an important outcome. The presence of the World Heritage Volunteers and the local media attention creates more awareness among the local population. Moreover, the World Heritage Volunteers become international ambassadors for the preservation of World Heritage Sites.


The project is organised by Liniebureau Nieuwe Hollandse Waterlinie in cooperation with SIW Internationale Frijwilligersprojecten. Every year different partners, such as nature organisations, municipalities and fort owners, participate in the project.