Nederland - Bussum, Fort Werk IV

Fort Werk IV in Bussum is an unique fortress fort within the Nieuwe Hollandse Waterlinie (New Dutch Waterline). This defence line spans 85 kilometres; it 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.

Naarden - one of the fortified towns - is located in the foothills of a high sandy area and remained a weak spot in the waterline; inundation was not possible in this elevated area. Due to the improvement of the artillery, especially the range of the cannons, the fortress of Naarden had to be defended from a greater distance. It was therefore decided to construct a circle of five fortresses around Naarden in the period from 1868 to 1870.

Four of the five mainly earthen works have meanwhile disappeared. The largest fortress, Fort Werk IV, has been preserved. It is built on a rather high point and is a fortress without water. It only has a ‘dry moat’, containing a wall with loopholes as a physical barrier. This crenellated wall is unique in the Netherlands and one of the main reasons why the fort is a National Monument. The Nieuwe Hollandse Waterlinie has been on the UNESCO World Heritage List since July 2021.

Fort Werk IV has been restored to its former glory. As of July 2018, the fort is owned by theatre Spant! and nowadays used for business meetings and other events. The fort is freely accessible.