The Nevenbatterij van het fort bij Vijfhuizen is a defence battery that is a part of the old defensive line constructed to defend parts of the Netherlands from invasion. The defence line was constructed over several decades between the end of the 19th, and beginning of the 20th century. The defence line uses water to defend the land from invasion – it was designed to quickly flood strategic points around the region. The line also serves as a safe retreat for important officials and military personel. It is now a UNESCO protected monument.
